[MegaBlues]

2.5x costs, so your 20 FP spell now costs 60? No no.

Silence is definitely an issue, but magic is nowhere near strong enough to warrant a status effect this strong, or that strong. I'd be in favor if it was a charm or hesitation-like effect for magic only, or if it increased costs by level%. But it should be a minor effect for how much it would affect.