msem-instigator

You may look at the top card of your library any time.
Once each turn, you may cast a spell from the top of your library.
Whenever you cast a spell from a library, create a 1/1 blue Elemental creature token with vigilance.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Leotau Rider encourages a creature, that creature gains trample until end of turn.

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 onto Lerithan Rebel, it deals 1 damage to any target.

Flying

Enchant creature
Enchanted creature and all other creatures with the same name as that creature can't attack or block.

At the beginning of combat on your turn, create a 1/1 colorless Servo artifact creature token. It gains haste and attacks this turn if able.
Whenever a creature you control dies, you may pay {1}. If you do, put a +1/+1 counter on target creature.

When Lethal Storyboarding enters, create two 1/1 colorless Construct Actor creature tokens.
Whenever a creature you control deals combat damage to a player or planeswalker, sacrifice it. When you do, choose one —
• Return a creature card with mana value 3 or less from your graveyard to the battlefield tapped.
• Draw a card.

Whenever Leyline Tracer attacks, exile the top card of your library. Until end of turn, you may play that card.
Ascend—{B}, Discard two cards. ({B}, Discard two cards: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

Other Wolves and Werewolves you control have haste.
Leyran Hunting Pack gets +1/+1 for each non-Human Werewolf you control.

Equipped creature has double strike.
Whenever equipped creature attacks, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Abilities of Idols you control that target equipped creature cost {1} less to activate.
Equip {2}{W}

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Discard up to two cards, then draw that many cards plus one.
3 | For each color of mana spent to cast this spell, add one mana of that color.

This spell costs {2} less to cast if you've cast another spell this turn.
Draw two cards, then put a card from your hand on top of your library.

Any number of target creatures you control each have base power and toughness 3/3 and become Beasts in addition to their other types until end of turn.
Reconstruct {2}{G}{G} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

When Life from Death enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Whenever a nontoken creature you control dies, create a 1/1 green Saproling creature token.

You can't cast this spell unless you have at least 5 life more than your starting life total.
Ward—Pay 5 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 5 life.)
{3}{W}{B}, Discard Life's Bride: Exile target nonland permanent. You gain life equal to its mana value.

Destroy target creature. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

When Lifespark Alchemist enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Whenever Lifespark Alchemist or another creature dies, each opponent loses 1 life.

Enchant creature
When Lifted Spirits enters, create a 1/1 white Spirit creature token with flying.
Enchanted creature gets +1/+1 and has flying.

Light the Fuse deals 3 damage to target creature or planeswalker. Whenever a permanent dealt damage by Light the Fuse this turn dies this turn, repeat that process.

When Lightblessed Claymore enters, attach it to target creature you control.
Equipped creature gets +2/+0 and has lifelink.
Equip {4}

Lightning Ripple deals 4 damage divided as you choose among any number of target creatures and/or planeswalkers.

If you would harmonize while this spell is on the stack, you may instead put three thunder counters on this spell.
Lightning and Thunder deals X damage to any target, where X is 3 plus the number of thunder counters on Lightning and Thunder.

Whenever Lightseeker Nymph perseveres, search your library for a basic land card, put it onto the battlefield tapped, then shuffle. (A creature perseveres when it survives damage.)

Whenever another artifact you control enters, put a +1/+1 counter on Lightsteel Enforcer.