Waterknot

Enchant creature
When Waterknot enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Overflowing Insight

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Sworn Guardian

Unsummon

Return target creature to its owner's hand.

Frilled Sea Serpent

{5}{U}{U}: Frilled Sea Serpent can't be blocked this turn.

Windstorm Drake

Flying
Other creatures you control with flying get +1/+0.

Waterkin Shaman

Whenever a creature you control with flying enters, Waterkin Shaman gets +1/+1 until end of turn.

Cloudkin Seer

Flying
When Cloudkin Seer enters, draw a card.

Windreader Sphinx

Flying
Whenever a creature with flying attacks, you may draw a card.

Wall of Runes

Defender (This creature can't attack.)
When Wall of Runes enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Island

Riddlemaster Sphinx

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Riddlemaster Sphinx enters, you may return target creature an opponent controls to its owner's hand.

Glint

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.)

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Soulblade Djinn

Flying
Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn.

Octoprophet

When Octoprophet enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)