Arbiter of Ash: impossible as minion build?

I have about 33% increased movement speed and its really impossible to beat the arbiter of ash. I am not going to try this again, its not possible and only costs a lot of currency and EXP. So i am wondering if anyone has an idea how to defeat him with a minion build or if this is simply not possible and the game is broken for minion builds?
The only thing (afaik) to gain movement speed is with shoes and with jewels. Some jewels have maybe 3% increased movement speed, so i might get another 6 or with some modifications 9% more. Should this be enough?

I wish i had some advice for you. I quit before they added the citadel beams and i only found 2 and i ripped in 1 of them so i wasnt even remotely ever close to trying arbitor.

With the change to the chest piece, is there really even a reason to do this boss anymore?

Also with all the boss unique drops is it even going to matter if you can kill any boss outside of ssf?

I would like to "finish" the game, means at least for me, kill all bosses at least once. I dont need a great drop or so, its just "to have it done".

https://www.youtube.com/watch?v=aCAcyaVOC0Q

on hc

This guy made it look so easy: https://www.youtube.com/watch?v=02Vtrh-fIUw

After watching that I decided to give it a try but I failed the one shot mechanics that this guy doesn't seem to face at all. Was the fight changed or was he just lucky?

@mat they fixed that. If you leave and join the arena again, he has full live.
@suuta yeah, if you do that much damage, you might skip the entire one-hit-stuff, but i am not willing to spend 100 divs to get the gear coz i have a real life