Flying
Creatures can't attack you.

Flying
Whenever this creature attacks, target attacking creature without flying gains flying until end of turn.

Other creatures you control get +0/+1.

Flying
Whenever you cast an enchantment spell, put a +1/+1 counter on this creature.

Flying
Whenever this creature deals combat damage to a player, that player skips their next combat phase.

, : Tap target creature.

Double strike
Teleport — : This creature phases out.

: Return this creature to its owner's hand.

When Boareskyr Tollkeeper enters, target opponent reveals all creature and land cards in their hand. Choose one of them. That card perpetually gains "This permanent enters tapped."

Backup 1
Whenever this creature attacks, tap target artifact or creature an opponent controls.

Sliver creatures you control have double strike.

Backup 1
Flying, first strike, lifelink

When this creature enters, you may search your graveyard, hand, and/or library for an Aura card and put it onto the battlefield attached to this creature. If you search your library this way, shuffle.

Flying
: This creature gains first strike until end of turn. ( can be paid with one mana from a snow permanent.)

Flying
When this creature leaves the battlefield, choose an opponent who controls more lands than you. Search your library for a number of Plains cards equal to the difference, reveal those cards, put one of them onto the battlefield tapped and the rest into your hand, then shuffle.

Vigilance
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
Sacrifice Boromir: Creatures you control gain indestructible until end of turn. The Ring tempts you.

Battalion — Whenever this creature and at least two other creatures attack, this creature gets +2/+2 until end of turn.

Battalion — Whenever this creature and at least two other creatures attack, this creature gains lifelink until end of turn.

Whenever you cast a spell, you may gain ½ life for each word in that spell's name.

This creature enters with a number of +1/+1 counters on it equal to one plus the number of other creatures you control.
Alliance — Whenever another creature you control enters, put a +1/+1 counter on this creature.
When this creature dies, create a 1/1 green and white Citizen creature token for each +1/+1 counter on it.

Whenever this creature attacks while saddled, put a +1/+1 counter on each other creature you control. You gain 1 life for each of those creatures.
Saddle 2

Vigilance
, Sacrifice this creature: Destroy target legendary permanent that's an artifact, creature, or enchantment.

Lifelink
Whenever Brad Boimler becomes tapped, until end of turn, if one or more counters would be put on a permanent you control, that many plus one of each of those kinds of counters are put on that permanent instead.

While voting, you get an additional vote. (The votes can be for different choices or for the same choice.)

Lifelink
Power-up — : Put two +1/+1 counters on this creature.

, : Target creature gets +1/+1 until end of turn. Activate only as a sorcery.

Flying, soulbond
As long as Breathkeeper Seraph is paired with another creature, each of those creatures has "When this creature dies, you may return it to the battlefield under its owner's control at the beginning of your next upkeep."