When the arcanist successfully uses the counterspell exploit, she can spend an additional point from her arcane reservoir to prepare that spell. The next time she prepares spells, any spells prepared through this greater exploit are lost. Spells not on the sorcerer/wizard list are prepared at their original level, and the arcanist must spend 1 point from her arcane reservoir each time she casts such a spell. The arcanist may copy a spell prepared through this greater exploit into her spellbook if it is an arcanist spell. The arcanist must have the counterspell exploit to select this greater exploit.
Book of Magic: 10 Arcanist Exploits, © 2016, Jon Brazer Enterprises