Sometimes a spell is so much fun to cast that you've just got to do it again, and this spellcaster's tool is the perfect thing to keep you charged up and ready to provide an encore when just one casting isn't enough!
Staff of Spell Echoes
Staff, rare (attunement to a spellcaster required)
This staff of silvery metal is hollow and makes a gentle moaning sound when swung quickly through the air. The staff has 7 charges and regains 1d6+1 expended charges daily at dawn. If you expend the last charge, roll a d20. On a 1, the staff loses its properties and becomes a nonmagical quarterstaff.
When you cast a spell while holding the staff, you can recapture some of the spell energy of the spell you have just cast by expending a number of charges equal to the spell’s level (treat a cantrip as level 1 for this purpose). On your next turn, you can re-cast the same spell without expending a spell slot. If you do not re-cast the spell on your next turn, the recaptured magic dissipates and the effect is wasted.