Defender, flying, vigilance
As long as you control two or more other creatures with defender, Fortunous Windhorse may attack as though it didn't have defender.

You have hexproof and can't cast creature or planeswalker spells.
No more than one creature can attack you each combat.
Whenever you cast a spell, you gain 1 life.

Flash
Flying
When Rescuer of the Lost enters, you may return another target creature you control to its owner's hand.

Unite with one or more creatures
When Combat-Form Instructor unites creatures, put a +1/+1 counter on each creature it united.

Whenever you cast an instant or sorcery spell from your hand, you may cast target instant or sorcery card with lesser mana value from your graveyard without paying its mana cost. If that spell would be put into your graveyard this turn, exile it instead.

Unite with one or more creatures
When Monastery Flagdancers unites creatures, return up to X target nonland permanents to their owner's hands, where X is the number of creatures it united.

Master of Caldera Elemental
{T}: Add {R}{R}. Spend this mana only to cast Elemental spells or activate abilities of Elementals.

Master of Wrap in Flames
Whenever Solara's Pyromancer deals combat damage to a player, put a +1/+1 counter on it.

[+1]: Add {R}{R}. You may discard a card. If you do, draw a card.
[–X]: Solara deals X damage to each other creature and planeswalker.
[–8]: Solara deals damage to each opponent equal to twice the number of {R} in the mana cost of cards in your graveyard.

Trample

Unite with two creatures
When Guru of Tumbling Stone unites creatures, exile the top card of your library. You may play that card this turn.

Wrap in Flames deals 1 damage to each of up to three target creatures. Those creatures can't block this turn.

Haste
Unite with three creatures
At the beginning of your end step, return Sunflare Disciple to its owner's hand unless it has a +1/+1 counter on it.

Whenever Ujuraq, Elder Watcher enters or attacks, surveil 1.
Ujuraq gets +3/+3 and has trample as long as there are eight or more cards in your graveyard.

Whenever a land you control enters, surveil 1.
Exile three cards from your graveyard: Put a +1/+1 counter on Boundary Guardian. Activate this ability only once each turn.

Flying
Whenever Atrah of the First Word enters or attacks, you may search your library for a Mantra card and cast it without paying its mana cost. If you do, shuffle.

Flash
Flying
When Serene Mediator enters, counter target noncreature spell unless its controller pays {1}.

Whenever a creature you control becomes tapped, Sonam the Hunted deals 1 damage to each opponent and you gain 1 life.
Pay 5 life: Another target creature you control gains indestructible until end of turn.

Flying
When Seqineq, the Rising Sun enters, your life total becomes 7. When it does, Seqineq deals X damage divided as you choose among any number of nonplayer targets, where X is the amount of life you gained or lost this way.

This spell can't be countered.
Trample
Hexproof from mana value 3 or less

Haste
Whenever Emberwind Visionary attacks, look at the top six cards of your library. You may cast an instant or sorcery spell with mana value 1 from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Menace
When Anigul, the Setting Sun enters, each opponent discards a card.
Whenever Anigul deals combat damage to an opponent, exile up to two target cards from that player's graveyard. For each of those exiled cards, Anigul deals 1 damage to that card's owner.

Burning Dawn deals 4 damage to any target.
Invoke {4}{R}{R}

Enchant Totem
Enchanted Totem gets +4/+4 and has flying.
When Sunscale Totem enters, enchanted Totem deals damage equal to its power to each opponent.

When Stoic Sentinel enters, surveil 2.
{T}, Exile a card from your graveyard: Add one mana of any color.