Eh, I don't know, it might be possible if we either prevent him from building AP or we make Rylai's disabled on him.
Something like he has lots of slows when he can walk, then he stops, gets immobile, gets range and damage, loses cc and (some) tankiness.
He could actually be a form swapper! Channel to swap forms, on mobile he has a defensive tool inspired to WW E/ Sion W, an AoE slow+grounding, a midrange poke skillshot that marks his opponent for a proc of damage after 2 autos. Still lowest range (lowered to same as lvl 1 mini gnar), higher AS, if within melee range he does a melee attack that deals bonus physical and magic damage.
On immobile form, a sort of larger radius Amumu W that swipes in a circle instead of being continuous, an AoE high-damage spell that interrupts, a ground targeted fast missile that applies both onhit and spell effects. No MS, 600 range autoattacks.