Color Identity: U

Initial Card State
- Insidious Will in hand.
- Adaptive Training Post on the battlefield (with two or more charge counters on it).
Notable Prerequisites
- You have an instant or sorcery card in hand with enough mana to cast it.
- You have enough mana to cast Insidious Will.
Steps
- 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 Insidious Will by paying its mana cost, targeting the spell cast in step 1.
- Adaptive Training Post triggers, copying Insidious Will, with the copy targeting the original Insidious Will.
- Resolve the copy of Insidious Will, copying the original Insidious Will, with the copy targeting the original Insidious Will.
- Repeat step 5.
Results
- Infinite magecraft triggers.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).