Buff Ivern. Make him tankier.

Ivern at level 1 or level 18 gets his candy ass ripped more new holes than a block of swiss cheese by Volibear, late game Rengar one shots him, mid to late game Kha'zix 2-3 shots him, Xin Zhao and Nocturne brutally murder him, Nocturne literally just eats Ivern's root. Ivern isn't supposed to be a damage dealer, he hates killing, so making him tankier is the only option.

Give him back the flat 5 MS you took from him, all the other nerfs make that nerf completely unnecessary, and give him a flat +10 armor. (actually on reflection +5 would be fine) That+ the +5 armor rune will actually allow him to survive, imagine that. He doesn't have the same issues vs. casters, not as bad, and his typical build tends to have a good amount of MR on it, so no MR buff is required.