msem-instigator

Play with the top card of your library revealed.
You may cast Elemental spells from the top of your library.

Defender
{1}{U}: Sea Wall gets +0/+1 until end of turn.
Whenever Sea Wall perseveres, you may return target creature an opponent controls to its owner's hand. (A creature perseveres when it survives damage.)

{U}, Sacrifice Seal of Insights: Look at the top four cards of your library. Put one into your hand and the rest on the bottom of your library in any order.

Cards in graveyards lose all abilities.
Cards in graveyards can't be the target of spells or abilities.

Another target player reveals their hand. You may choose a nonland card from it. That player discards that card.
Fuse (You may cast one or both halves of this card from your hand.)

Reveal the top five cards of your library. You may put an instant or sorcery card from among them into your hand. Put the rest into your graveyard.

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Searing Blasphemy deals 2 damage to target creature. If that creature is an Angel, Searing Blasphemy deals 5 damage instead.

Target creature gains winnow until end of turn if you attacked this turn. Searing Insult deals 2 damage to that creature. (Damage dealt to it also causes its controller to lose that much life.)

Reverberate {3}{R} (When you cast this spell, copy it if you paid its reverberate cost. You may choose new targets for the copy.)
Searing Pulse deals 2 damage to any target.

Haste
Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Search your library for up to four basic land cards with different names, reveal them, put them into your hand, then shuffle.

({T}: Add {G} or {U}.)
Secluded Cascade enters tapped unless you control two or more basic lands.

Defender (This creature can't attack.)
Adorned — Secluded Wildborn can attack as though it didn't have defender as long as it's equipped and/or enchanted.

Look at the top two cards of target player's library. Put one of those cards on the bottom of their library and the rest on top.
Fuse (You may cast one or both halves of this card from your hand.)

Scry 2, then draw two cards.
You have no maximum hand size for the rest of the game.

Equipped creature has hexproof and distorted. (It can be blocked by tapped creatures but not untapped creatures.)
Equip {1}

When Seeker's Guardian enters, reveal the top card of your library.

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

Another target player reveals their hand. You may choose an instant or sorcery card from it and cast it without paying its mana cost.
Fuse (You may cast one or both halves of this card from your hand.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on Sejiri Skyhunter, it gains flying until end of turn.

{3}: Sellsword Contraption becomes the creature type of your choice until end of turn.

[+1]: You gain 1 life. Put a +1/+1 counter on up to one target creature.
[–3]: Exile target creature. Its controller gains life equal to its power.
[–8]: You get an emblem with “Creatures you control get +1/+1 and have double strike and lifelink.”

At the beginning of your draw step, draw an additional card and you lose 1 life. Then if you have six or fewer cards in hand, sacrifice a creature.

Target player discards two cards. If a creature you control died this turn, that player loses 2 life.