There is no world where angels fear to tread.

Maelstrom Archangel

Flying
Whenever this creature deals combat damage to a player, you may cast a spell from your hand without paying its mana cost.

Dominaria United Commander

Flying
Whenever Maelstrom Archangel deals combat damage to a player, you may cast a spell from your hand without paying its mana cost.

Jumpstart

The List

Conflux

Flying
Whenever Maelstrom Archangel deals combat damage to a player, you may play a nonland card from your hand without paying its mana cost.

If you cast a card this way, you're casting it as a spell. It can be countered.

If you cast a card with X in its cost this way, X must be 0.

If you cast a card “without paying its mana cost,” you can't choose to cast it for any alternative costs, such as evoke or the alternative cost provided by the morph ability. However, you can pay optional additional costs, such as conspire, and you must still pay mandatory additional costs, such as the one on Goldmeadow Stalwart.

If you want to cast a card this way, you cast it as part of the resolution of Maelstrom Angel's triggered ability. Timing restrictions based on the card's type (such as creature or sorcery) are ignored. Other casting restrictions are not (such as “Cast [this card] only before attackers are declared”).