Feat: Versatile Spellstrike

You can channel the entire realm of possibilities of your spellbook into an attack.

Once during your daily preparations, you can use a spell slot to hold that infinite potential, rather than using it to prepare a spell. When you make a Spellstrike, you can expend this special spell slot to immediately prepare and cast a spell from your spellbook at 2 ranks lower than the slot's rank. (As normal for preparing spells, you can use a spell of an even lower rank, heightening it accordingly.)

You don't have any spell prepared in that slot until you cast from that slot.