msem-instigator

You may put a permanent card from your hand onto the battlefield. If it's a planeswalker, it enters with five loyalty counters rather than any other amount, and you may activate its loyalty abilities this turn any time you could cast an instant.

Ward {2}
Whenever one or more Auras you control enter for the first time each turn, adjudicate. (Create a white enchantment Aura token with enchant creature and “Sacrifice this token: Untap enchanted creature.” attached to target creature.)
Keeper of Secret Havens gets +1/+1 for each Aura you control.

Whenever a land you control enters, crystallize.
{10}: Shuffle any number of other permanents you control into their owner's library. Mill that many cards. Put all permanent cards milled this way onto the battlefield. Activate only during your turn and only once each turn.

Deathtouch
When Pestilent Scavenger enters, you may mill three cards.

Hexproof
Whenever an opponent casts a spell or draws a card, draw a card.

Flash
Flying
If an effect an opponent controls would cause them to take an extra turn, you take an extra turn instead.
{G}{U}: Return another creature you control to its owner's hand. Activate this ability only once each turn.