Dark Assassin 闇アサシン Showcase (Granblue Fantasy グラブル)

I have to be honest, I never tried Assassin seriously as a class until today and I have to say that I understand why a lot of people end up using it for doing solo battles against hard raids.
It packs so much power at the cost of having to prepare materials for each battle. The cost of these items is not too harsh either (at least for an advanced player with lots of mats piled up).
Doing Assassin skills (overdrive or break) every turn is...downright hilarious.
I seriously wonder what they can do to improve this one in a possible EX2 class...