Author of Shadows

Target opponent reveals their hand. You choose a nonland card from that player's graveyard or hand and exile it. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.

If a nontoken creature an opponent controls would die, exile that card with an ice counter on it instead.

You may cast spells from among cards in exile your opponents own with ice counters on them, and you may spend mana from snow sources as though it were mana of any color to cast those spells.

Target opponent reveals their hand. You choose a nonland card from that player's graveyard or hand and exile it. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.

Devour Intellect — When this creature enters, each opponent exiles a card from their hand until this creature leaves the battlefield.

Body Thief — You may play lands and cast spells from among cards exiled with this creature. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

Emerge from artifact (You may cast this spell by sacrificing an artifact and paying the emerge cost reduced by that artifact's mana value.)

When this creature enters, target opponent exiles the top card of their library, a card at random from their graveyard, and a card at random from their hand. You may cast a spell from among cards exiled this way without paying its mana cost.

When Hama enters, target opponent mills three cards. Exile up to one noncreature, nonland card from that player's graveyard. For as long as you control Hama, you may cast the exiled card during your turn by waterbending rather than paying its mana cost, where X is its mana value. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for .)