Arcanist › Arcane Reservoir

Metamixing (Su)

The arcanist can expend 1 point from her arcane reservoir to add a metamagic feat that she knows to a spell as she casts it without affecting the casting time (though using a higher-level spell slot as normal). She can use this ability to add a metamagic feat to a spell that she prepared using a metamagic feat, although she cannot add the same metamagic feat to a given spell more than once.