It is good that Cho can have different builds and roles, but they must be DIFFERENT.
Tanky Cho shouldn't be able to assassinate carries and Mage Cho, while being supposed to be "assassin resistant", shouldn't basically be an off-tank. #1. Lower his base damages and also a bit the scalings. #2. Bugfix his W so that it doesn't proc anyway if you flashed out #3. Don't nerf R damage and move the base damage of E into % enemy max health This allows tank him to be a bunker threat for enemy frontliners. #4. R health gain should become a % of his max health AND resistances This prevents mid Cho from gaining absurd free tankiness while making tank Cho unkillable in exchange for the lost damage #5. Passive should scale of max resource + regen for both mana and HP This reduces mid'gath's midgame sustain compared to the spike from HP items on Top'gath.