Royal Assassin

Azure Beastbinder

Vigilance
This creature can't be blocked by creatures with power 2 or greater.
Whenever this creature attacks, up to one target artifact, creature, or planeswalker an opponent controls loses all abilities until your next turn. If it's a creature, it also has base power and toughness 2/2 until your next turn.

Alluring Siren

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

Aetherize

Return all attacking creatures to their owner's hand.

Shipwreck Singer

Flying
{1}{U}: Target creature an opponent controls attacks this turn if able.
{1}{B}, {T}: Attacking creatures get -1/-1 until end of turn.

Lagoon Breach

The owner of target attacking creature you don't control puts it on their choice of the top or bottom of their library.

Horned Loch-Whale

Flash
Ward {2}
This creature enters tapped unless it's your turn.

Horned Loch-Whale // Lagoon Breach

Wall of Frost

Defender
Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step.

Sweep Away

Return target creature to its owner's hand. If that creature is attacking, you may put it on top of its owner's library instead.