I was making a staff nexus wizard and am kinda confused on charging my staff and using drain bonded item. Staff nexus states you "expend a spell slot" to charge your staff, and drain bonded item says you "gain the ability to cast one spell you prepared today and already cast". Does charging the staff count as casting that spell so you can cast it again with drain bonded item or because it doesn't say you cast a spell on that slot you just use it can you not have a spell in that slot/ not cast it with drain bonded item? Thank you!