[@NRVNQSR]: My mistake about the skill. Masters can't have Servant skills but with how bad some characters I've seen pop up in old Fate RP's on another site have been I was worried for a moment.

Still, the combination of things here is something I have to take issue with.

If he can perceive what any magic does instantly it's very hard to counter him and he could still easily figure out what NP is by what it does, and therefore figure out what the Servant's identity is. He can also very easily counter any defensive magecraft anywhere. This comes from a "fun in RPing" angle, too. Wouldn't it be more fun to write him needing to work really hard for infiltration and using counterspells to penetrate defenses then just coasting through it?

The same kind of goes for the Noble Phantasm, honestly. Also, wouldn't the NP have a really heavy mana cost? And possibly need some weird things to use it? Remember, Bazett has to spend days making the iron balls for Fragarach.