msem-instigator

Althestran Legionnaire gets +1/+1 for each Aura attached to it.

When Traversing the Hellwastes enters, create a 1/1 green Scout creature token. It gains haste until end of turn.
Whenever a creature you control enters, you may pay 2 life. If you do, draw a card.

When Pensive Muse enters, create a white Aura enchantment token named Seal's Love attached to target creature you control. The token has enchant creature and “Enchanted creatures you control get +1/+1.”

At the beginning of your upkeep, you may return a nontoken creature you control to its owner's hand. If you do, create a 2/2 green Elk creature token.

Trample, ward {1}
Whenever you gain life, put a +1/+1 counter on Unrelenting Noble.
{1}, Sacrifice a permanent: You gain 2 life.

Return Portal to the Unknown to its owner's hand: Add {U}{U}{U}. The next card you cast this turn can be cast as though it had flash.

Target player sacrifices an enchantment. You gain 4 life.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Curious Cubs has first strike as long as its attacking.
When Curious Cubs has three or more +1/+1 counters on it, remove them all and transform it.

When Horn of Seasons enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equipped creature gets +3/+0.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

You have no maximum hand size.
{T}: Add {C}.
{3}, {T}: Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Flash
Enchant creature
As Legacy of Northrime enters, choose a creature type.
Enchanted creature gets +1/+4 and is the chosen type in addition to its other types.

Abandoned Battlefield enters tapped if you control another nonbasic land.
{T}: Add {U} or {B}.

Destroy target creature with power 4 or greater. You gain 2 life.

When Militia Commander enters, create a 1/1 white Peasant creature token.
Other Citizens and Peasants you control get +1/+1.

Enchant creature
When Shrouded Spoils enters, draw two cards.
Enchanted creature can't be blocked.

Enchant player
Enchanted player's maximum hand size is reduced by two.

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

Haste (This creature can attack and {T} as soon as it comes under your control.)
Whenever a creature you control attacks, each opponent loses 1 life.

Bulwark — At the beginning of each upkeep, if you control a creature with toughness 4 or greater, Fortress Sentinel gains hexproof until end of turn.

First strike
Whenever Sighted-Caste Knight deals combat damage to a player, draw a card.

Put a +1/+1 counter on target creature. (Then exile this card. You may cast the creature later from exile.)

Clutch Shot deals 2 damage to target creature or planeswalker. If you control six or more lands, Clutch Shot deals 4 damage instead.

Ward {3}

Your opponents can't search libraries unless they pay {2}.
[+2]: If an opponent has more life than you, you gain 2 life.
[0]: If an opponent controls more creatures than you, you create two 1/1 white Gnome creature tokens.
[–4]: Search your library for a creature card with mana value 2, put it onto the battlefield, then shuffle.

{1}: Exile target card from a graveyard. That card's owner may scry 1.