Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Alluring Siren

{T}: Target creature an opponent controls attacks you this turn if able.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control this creature.

Dulcet Sirens

{U}, {T}: Target creature attacks target opponent this turn if able.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)