Absorbed Studiosus

You may choose not to untap Absorbed Studiosus during your untap step. If you don't, put a charge counter on it.
When Absorbed Studiosus becomes untapped,
you may cast an instant or sorcery card with converted mana cost equal to the number of charge counters on Absorbed Studiosus from
your hand without paying its mana cost. Then remove all charge counters from Absorbed Studiosus.