We need a Champion who takes notes from the Metroids in Metroid: Samus Returns (3DS)

Kha'Zix might evolve new adaptations each time he levels his ultimate, but that doesn't involve him transforming into an entirely new body each time. Meanwhile, you look at the Alpha, Gamma, Zeta, and Omega Metroids from Samus Returns. Each evolution is larger, deadlier, and fights differently compared to its previous stage. For instance, the Gamma Metroids will try to run away if they start taking too much damage, but the Omega Metroids will just barrel through your attacks and try to bite your head off. It's a very different experience each time it evolves.

I know making such a Champion for League would probably not work, but we wouldn't necessarily have to go with "get a completely new moveset at levels 6, 11, and 16". At the very least, a Champion with this gimmick would get a drastic change in appearance, stats, and maybe abilities become empowered as a result of evolving. For instance, an ability that slows at a lower stage of evolution could instead stun once you reach your highest form.

Just some food for thought as a result of me watching Youtube videos of no-damage boss runs.