Defeat the Kraken in under 5 mins. On 2-2 main quest not the side quest.
The goal he is to constantly throw objects at him when it's in phase 1 (where you can't run up a hit him).
During phase two to run towards him to generate the slug things and clear them out.
Phase 3 dodge when he lunges and get a few LT+B hits in and then when he hurls the missiles catch them and toss hem back.
Once you get the hang of it it's very doable on any difficulty