The disadvantages of Prest 2 & 3 should have been flipped. Avatar of Essence already boosts his units’ damage so letting him have as many fragments as he can get, which buff his units, and then add in the Avatar which makes them stronger while devolving the enemies - jeez, way way overkill. They can manage without the Avatar. And when you use your legion, you get a lot of them with more fragments. So this should change to: get as many fragments as you can in 20-25 mins but you don’t get the avatars. And I’m undecided if his units should still cost more after my suggested change. Maybe just 10-15% more, instead of 25%.
In Prest 3, when solo’ing with Zeratul or relying on him doing a lot of killing, not having have the Avatar to boost him or devolve enemies is…off. The shadow cleave cooldown could be better spread among the 3 fragments and let him have the avatars. Aside: this prestige would be super-ideal with the current mutation and solo with canons. (Zeranon? Canotul?)
Also, prest 3 seems like it was meant for solo with Zeratul, since you wouldn’t get the 3rd fragment or any of its benefits for his units: shield guard without reflection shield, void templar without respawn, immortals without their health regen barrier, etc.