Zilean's ult is the only support ult that doesn't cost 100 mana
Chronoshift mana cost: 125 / 150/ 175
Can we fix that? Zilean's changes were meant to modernise him and yet both when he initially got changed, and then later got buffed (with a variety of mana cost reductions!), his ult's mana cost being outdated was ignored. Since Sona's Crescendo was (finally) changed to cost 100 mana at all ranks, Chronoshift has been the only support ultimate in the game to scale up in mana cost with level (unless you count Zyra as a support, but that's controversial).
Given Zilean still seems a bit weak, I think we could probably make this change quite easily? It seems like as good a place to start with buffs as any, honestly.
(p.s. Stranglethorns could do with a cost reduction too)

