Desdemona, Desperate Healer

{t}: Put a -1/-1 counter on Desdemona, Desperate Healer. When Desdemona dies
this turn, if it had three or more -1/-1 counters on it, return it to the battlefield transformed under your control with a study counter on it for each -1/-1 counter it had.
____________________________________
"My only hope lies in this cursed book."