Casters Skill Merciful Sky
To upgrade Casters skill from Bestial Sky to Merciful Sky you need to kill 5 of the Nephilim enemies you find throughout the game Once you do this go to your private room and youll get a conversation and after that the skill will be upgraded
Noble Phantasms
These can be unlocked on Chapter 5 before the boss battle with Assassin
Sabers Skill Thunderous Applause
Use 100200 items during your run through the arena Youll know you used enough items when you speak with Saber in your private room and she starts talking about wasteful spending When you see that conversation youll get a confirmation that Artillery Applause has been upgraded to Thunderous Applause new skill costs 60MP instead of 40MP
Special Boss
Finish all of Taigas requests on a second playthrough and after the 7th week she will say that the arena is dangerous Youll find the special boss at the end of the floor
