Bunny,
let me easily convince you that Lord Loki best buddy is Rumple.
WHY?
They combine for best comboes!
HOW?
You take away ‘‘probability’’ factor?
TELL ME MORE!
First cast Rumple… you get either HEAL, DMG OR HEAVY MANA DEBUFF. Whatever you got, you then know what you wish to do with Loki (who to target). Go for extra dmg to clean board, go for heal if you was hoping for Rumple heal, or punish even harder enemy with debuffs on top of Rumple debuffs 
// Besides he is one of best tanks in game ! Two specials heavily impaire enemy to generate mana and what they can do otherise… the other one is major HP boost with strongest status ailment immunity in game 