How does Mindbreak Trap interact with [LCI] Flashback and [THB] Underworld Breach?
Let's say the conditions exist to cast [[Mindbreak Trap]] for its alternate {0} cost.
If you cast and resolve [[Flashback]] and target Mindbreak Trap in your graveyard, can you cast Mindbreak Trap for {0}? Or do you have to pay {2}{U}{U}?
Alternatively, if your [[Underworld Breach]] is on the battlefield and you have access to casting Mindbreak Trap from your graveyard, do you still have to pay {2}{U}{U} and exile three cards from your graveyard? Or can you pay {0} and exile three cards instead?
Edit to the title: [SOS] Flashback