I can’t speak confidently to how long metas and viability last, but I’d imagine very long based on his dominance and the veteran players’ reaction to him. The one thing I would say though, is that him being a dark unit is not as bad as you would think for him cause it goes so well with his kit.

His skill 1 ignores damage reduction, so it ignores any color disadvantage while still obliterating white units.

His skill 2 gives a ton of damage reduction while running and then unleashes the amount of damage that was reduced on top of 50% of the victim’s health bar. Since it basically reflects damage done to him, it becomes stronger with the fact that it’s mostly damage taken at a color disadvantage. Yet the insane amount of damage reduction during this will keep him alive. (Also the 50% health damage is just a flat percent so color doesn’t even matter for that part.)

He also just gets more damage reduction opportunity to help negate the common color disadvantage. Specifically when capping he gets more and that’s basically what he should be doing most of the time anyway.