Martyr of Frost

{2}, Reveal X blue cards from your hand, Sacrifice this creature: Counter target spell unless its controller pays {X}.

Soratami Mindsweeper

Flying
{2}, Return a land you control to its owner's hand: Target player mills two cards.

{U}, {T}: Return target permanent you control to its owner's hand.

Flying (This creature can't be blocked except by creatures with flying or reach.)
{1}{U}: Target player reveals the top card of their library.

When this creature enters, put target creature on top of its owner's library.

Defender
Your maximum hand size is increased by one.