singed rework or changes in future?

singed supposed to be ap tank. right now i think he is weak. his R gives him extra stats for 25 seconds but.... since he has lot of HP bcs of his passive the regen is not seen so much i know it shouldnt be something like mundo/garen but it should be something that can keep you alive so he should get some % hp regen instead of flat amount or be increased based on missing health. armor/mr bonus is something that cant keep you alive everytime so he should get changes and get % dmg reduction. for mana regen . if it cant keep his on enoughf mana to have q toggled its bad when he has 0 mana avaible. and if you put his q to his passive and give him new ability to his Q or move E to Q and new E he should be more fun. or atlest give him some extra scaling to his passive similar to ryze´s passive