Adaptive Training Post | Return the Favor

Cards

Return the Favor in hand.
Adaptive Training Post on the battlefield (with two or more charge counters on it).

Cast the additional instant or sorcery by paying its mana cost.
If
Adaptive Training Post had two charge counters on it, it triggers, putting a charge counter on it.
Holding priority, activate
Adaptive Training Post by removing three charge counters from it, copying the next instant or sorcery spell you cast this turn.
Cast
Return the Favor by paying its mana cost, targeting the spell cast in step 1.
Adaptive Training Post triggers, copying
Return the Favor, with the copy targeting the original
Return the Favor.
Resolve the copy of
Return the Favor, copying the original
Return the Favor, with the copy targeting the original
Return the Favor.
Repeat step 5.