Eternal Knight mob seems overtuned

They are really not that hard to deal with as long as you're not relying on spamming the same projectile attack while sprinting throughout the entire map.

There are many long range spells/aoe attacks that do not trigger their reflect.

Like the base spell on a voltaic staff:

https://imgur.com/Rr2BdDc

Another option is just stand right in their face, strafe the attack and blast them while their shield is down.

I also like how it's generally assumed that armour is worthless, but in situations like this armour completely removes any threat from these knights projectiles.