Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Barrin, Tolarian Archmage

When Barrin, Tolarian Archmage enters, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Invisible Stalker can't be blocked.

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Tempest Djinn

Flying
This creature gets +1/+0 for each basic Island you control.

Merfolk Trickster

Flash
When Merfolk Trickster enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Essence Scatter

Counterspell

Nightveil Sprite

Flying
Whenever Nightveil Sprite attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.