Slither Blade

Smoke Shroud

Enchant creature
Enchanted creature gets +1/+1 and has flying.
When a Ninja you control enters, you may return Smoke Shroud from your graveyard to the battlefield attached to that creature.

Counterspell

Of One Mind

This spell costs {2} less to cast if you control a Human creature and a non-Human creature.
Draw two cards.

Moonblade Shinobi

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Moonblade Shinobi deals combat damage to a player, create a 1/1 blue Illusion creature token with flying.

Ninja of the Deep Hours

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Ninja of the Deep Hours deals combat damage to a player, you may draw a card.

Unsummon

Return target creature to its owner's hand.

Brinebarrow Intruder

Flash
When Brinebarrow Intruder enters, target creature an opponent controls gets -2/-0 until end of turn.