[3.7] Scion Power Siphon | 2-4M+ Shaper DPS | Budget Clear up to T16

Firstly, I'd like to point out that this is my first build guide on a build I've came up with, although I have PoB folders with loads of builds and clunky fun mechanics, this is the first one simple enough and easy to understand and play with and therefore I've decided to write a guide on.This build is currently a work in progress build (this guide is getting updated regularly though).
The motivation behind the making of this build is that Power Siphon has alwyas been an underwhelming skill to use as Kinetic Blast has always been the better option for every wander for clear speed (due to 4 explosions on hit). The second reason behind the making of this build is the fact that although there are great Scion builds out there, the number of scion builds is still very low and although I've made a small number of builds of my own, I felt like contributing to the Scion build pool with a different build using a lesser used skill. The third reason is that in 3.3 Power Siphon was slightly buffed while Kinetic Blast was slightly nerfed in 3.4. Finally, the last reason behind making this build is because 3.8 is likely be focused on either a Bow or a Wand rework/overhaul.
Having that said, what is shown on this post is based on the 3.7.- patch and might get better on 3.8 and worst case scenario will be the same, since Power Siphon is so bad atm that it wont get nerfed anytime soon.

This is a fun build to show some love to Power Siphon, it still should do all content in the game and have a above average clear speed while on a budget (Inpulsa being optional).

Pros:
+Satisfactory Shatters and Blasts;
+Awesome clear speed;
+Budget as League Starter;
+SSF is more than possible (w/o inpulsa);
+Scaling can reach 3M+ dps and 6k eHP;
+Somewhat beginner friendly;
+Extremely flexible & customizable;
+Smack'em with 1 click = screen clear;
+It's scion, it's sexy;

Cons:
-Single target isn't amazing;
-Survivability can be an issue;
-Not an HC build;
-KB is probably still better;
-Scaling is not top-tier;

1) Power Siphon generates power charges on killing mobs and on hitting rares and uniques, benefiting from 'Elder Power' node. Therefore with this skill we always have power charges. We scale with power charges, 10% crit multi per power charge as well as 10% increased dmg per power charge and you can also get Elder wand suffix 'of the Elder' which gives us 10% increased damage per power charge.

2) Power Siphon also has integrated Culling Strike, which makes this skill essentially a 2L by itself, but there's more...

3) Vaal power siphon already was a good enough skill, it clears the whole screen and can't be evaded.

4) Power Siphon fires 8 additional projectiles at lvl 21, making it 9 projectiles effectively and therefore there is no need for GMP, saving us another useful link, unlike the Kinetic Blast counterpart.
We already have a 4L skill in a single gem (Power Siphon + GMP + Cull + PCoC), doesn't it sound good enough already?

5) With HoI shatters we enhance our clearspeed a bit, combined with Inpulsa's effect we have ice and shock explosions for that extra crispy clear experience.

6) Speaking of shatter and shock, with 95%-100% crit chance we have 95%-100% chance to freeze/chill and shock.

7) Last but not least, power siphon has another special mechanic, besides being a 4L in one gem: projectiles aim themselves at the enemies. This means that you don't even have to aim to the mob packs, the projectiles automatically go to them individually.

8) Extra: Although not intended, don't be ashamed to use Barrage with Ele Focus for single target in case you feel like power siphon alone isn't enough. Shock with power siphon and blast bosses with Barrage. If you plan on playing like this (wont Reccomend due to links and mechanics), you'll want to get some 5L Gloves with 'Socketed Gems are Supported by Level 18 Slower Projectiles / 20% Increased Projectile Damage' and Sacrifice other gem combos.

This build is played like most wanders, however there are some things to keep in mind..
Point Blank- Although we have 'Point Blank' our damage is still great at the distance (unlike with Kinetic Blast counterpart) this gives us the advantage to clear yellow mobs in one or two shots at t15. We can also play bosses safely at the distance: When doing Uber Lab I safely killed izaro's last phase with 4-5 shots at the distance, dodging his first ability and the follow-up. Keep this fact in mind since while you have 'Point Blank' you might want to get close the bosses and face-tank them, this might not be a good idea, keeping the bosses at mid way from you to the edge of the screen keeps you at tons of damage while safe from melee range;
Dodging- It's in your best interest to actively dodge attacks and projectiles, this build suffers from easy 1-shots from physical damage and even some spells so always keep on moving.
Use shield charge for general movement and Flame Dash for dodging.
Click-and-run- After playing for a while you will notice that you pretty much clear the screen with 1 or 2 clicks and therefore for the best map clearing experience you want to click, shield charge, click again, repeat. We're not running 'Queen of the Forest' here, so your clear speed comes from your movement skill.
Panic button- If you accidentally find yourself between 100 mobs after teleporting or opening a strongbox, feel free to shoot up Vaal Power Siphon to instantly clear them all out.
Focus on survival- Don't worry about the damage, play safe, you will clear mob packs in 1 click and yellow mobs with 2-3 clicks, and even when you find a thougher mob, you can still spend 1 second to attack 5 times (5 aps) and he'll probably die anyways.

Main skill:(In order)
Power Siphon (21) - Added Lightning Damage (20) - Elemental Damage w/ Attacks (20) - Added Cold Damage (20) - Slower Proj. (20) OR Fork (20) (Single vs. Clear) - PCoC (20) OR Inc. Crit. Dmg(20);
Power Siphon lvl 21 adds another projectile, optional but reccomended;

Cwdt #1:
Cast when damage taken (7 to 13) - Projectile Weakness (10 to 16) - Summon Ice Golem (9 to 15) - Summon Lightning Golem (9 to 15);


Cwdt #2:
(Alternatively you can self cast Golems and add these instead)
Cast when damage taken (5) - Immortal Call (7) - Cold Snap (10)

Auras (Sorted):
Wrath - Precision (20) - Herald of Ice - Blood Rage

Movement:
Shield Charge - Fortify - Faster Attacks

Helmet:

Starkonja, Devoto's Devotion, Rat's Nest and Crown of Eyes are good unique choices that are easy or cheap to obtain. Besides those, a good rare helmet is the best option to go with.
For the enchantment either get '15% increased Power Siphon Attack Speed' for DPS (Reccomended) or get 'Power Siphon fires 2 additional Projectiles' for smoother map clear.

Chest:

You'll want to get either a good rare chest armour or alternatively and for extra clear you can go with Inpulsa's Broken Heart.
If you're going for a cheap 6L rare prioritize by order: +#(90+) to max. life, +#(100+) total elemental resistances;

Weapons:

Prioritize:
1)Added flat damage;
2)Attack speed;
3)Increased global crit multi;
4)Increased crit chance;
5)Increased lightning damage;

If Elder wand get '5-10% increased damage per Power Charge' as a priority!

Tip: In the final Path of Building setup, swaping the almost mirror-tier wand for a Piscator's Vigil you only lose less than 0.5M Shaper DPS (from 2.3M Shaper DPS to 1.8M Shaper DPS).

Gloves:

Prioritize:
1)Life;
2)Resists;
3)Flat added lightning damage;

Gripped gloves are nice for the projectile damage implicit;

Amulet:

Prioritize:
1)Max life;
2)Crit multiplier;
3)Increased damage with attack skills;
4)Flat added Lightning damage;
5)Resists;

Rings:

Prioritize:
1)Life;
2)Elemental damage;
3/4)Flat added damage;
3/4)Resists;

Alternatively, If you have some extra exalts lying around, you can get Precursor Emblem, Topaz Ring which has 3 mods for power charges. Look for this 3 mods:
-2% Increased Attack and Cast speed per Power Charge;
-5% Increased Damage per Power Charge;
-1/2 to 20 Lightning Damage per Power Charge;

This should cost from 30 to 100 exalts to even a so it's only theoretical for now.

Boots:

Rare boots are probably the best choice here for capping resists and getting +25% Movement speed minimum, however, there are some unique options that you may consider, such as Inya's Epiphany which give life, damage per power charge and chance to get max power charges when receiving a power charge, which may be useful against bosses.
The rares listed above (as of 15 Aug 2019) are extremely cheap and go for about 1c mid league.

Belt:

A rare belt, both Leather belt or Stygian vise are good options.
Focus on getting 120+ life as well as 80+ total ele res minimum, followed by elemental damage with attacks.

Flasks:

Diamond utility flask is pretty much mandatory, Cinderswallow, Vinktars (Attack Added), Silver and Atziri's Promise are good flasks to boost your DPS.
If taking Diamond and Silver flasks, make sure to roll Bleed and Freeze immuniy (interchangeable).

Jewels:
Prioritize:
1)Increased maximum life;
2)Global crit. multiplier;
3)Attack speed;
4)Flat Lightning and Cold damage;
5)Flat life;
6)Increased lightning damage;

Bandits:
Kill all (Reccomended) or Alira;

Ascendancy:
1)Elementalist - Reflect Immune, Extra Golem, Free 10% Penetration, Shock Buff, Herald Buff;
2)Inquisitor + Templar Path - Free 6% Penetration, Crit multi vs. Shocked, Enemy debuff;

Pantheon:
Your preference really...

Tips:
-We go for acrobatics, therefore get Evasion-based gear;
-While leveling go for 'Hired Killer' and 'True Strike' and later on re-spec those for better nodes;
-Early on spec into 'Forces of Nature' and when your tree reaches close to 'Primeval Force', respec 'Forces of Nature' temporarily for 'Primeval Force' as it gives more damage for 4 nodes as well;
-You can spec into 'Wandslinger' early or before getting Uber Lab done, after Uber Lab, respec those 4 passives for the elemental nodes in Templar to get 'Discipline and Training' faster;

https://pastebin.com/4NfCdWzf
DISCLAIMER:
Build in PoB can be improved by alot! I currently have better items than those listed on PoB! (Except wand!!!)

Disclaimer: No game progression guide here (such as 'get Normal lab after Piety', etc..), only tree, skill gems and general stuff.

Guide:
-Stock up on leveling items such as: Goldrim, Sadima's Touch, Wanderlust, Lifespring (Swap after getting Storm Prison), Belt of the Deceiver and if you want to use a Tabuila Rasa make sure to also pick up an Atziri's Foible because at 6L you'll be mana dry very often.
-Pick up Power Siphon and socket it, even if you don't want to used it early on, just to level it (not necessary);
-Use Kinetic Blast + Barrage while leveling;
-Swap out Kinetic Blast for your Power Siphon when you get double 'Storm Prison' wands or when you feel like it;
-As mentioned above, spec into 'Hired Killer' and 'True Strike' at the beginning of the tree;
-Try to get a nice 4L in case you're not rocking a Tabula;
-Socket Power Siphon + Added Lightning + Elemental Damage with Attacks + Added Cold OR Slower Proj; (if using Kinetic Blast get LMP or even GMP as the 4th link)
-If using Barrage, socket it with the same supports as Power Siphon; (Barrage will do more damage than power siphon as Single Target at any point in the build!)
-Get jewel slot as soon as you have an 'ok' jewel;
-Get Herald of Ice;
-Only get Wrath when you can sustain your mana;
-You can spec into Acrobatics early on if you feel like it;
-If you draw a line at the center of the Passive tree, you will want to go for the lower half of the tree first, since the upper part of the tree focus on Critical Strikes mostly;
-Only get Vaal Pact when you have good enough damage and picked up 'Blood Drinker';
-You can pick up 'Point Blank' whenever you feel like it;
-When you reach the node before 'Primeval Force', Respec 'forces of Nature' and spec into 'Primeval Force' (You still spec into 'Forces of Nature afterwards when you get more passive points!!);
-Follow the upper side of the tree by getting the power charge nodes on the way. Don't go for 'Assasination' and 'Trickery' just yet;
-Pick up both power charge nodes as well as 'Elder Power';
-Now that we have 5 Power charges up and running at all times, you can spec into critical nodes such as ''Assasination', 'Trickery', 'Heartseeker' and 'Throatseeker'. You can now respec 'True Strike' as we have very high crit chance;
-You should've stopped using Barrage by now as Power Siphon should be able to quasi-melt bosses in no time, saving you a 4L and skill slot;
-At this point you can follow the tree anywhere and even make you own adjustments;

Carcass T15 Gameplay sample video:

Most important aspect of this patch was the addition of "Barrage Support". Now our pre-awakening main link is as follows (by order):
1) Power Siphon
2) Barrage Support
3) Elemental Damage with Attacks
4) Added Lightning Damage
5) Lightning Penetration
6) Slower Projectiles

The BIS Awakening gems are the same ones but awakened!

The reason we don't pick elemental focus is because we want to shock enemies with crits