msem-instigator

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. Put a +1/+1 counter on each creature you control.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{3}{G}: Harmonic Recruit gets +2/+2 until end of turn. If you're in a renaissance, it gets +4/+4 until end of turn instead.

Whenever you cast an enchantment spell, you may pay {W}. If you do, put a +1/+1 counter on target creature.

Draw two cards. Each opponent draws a card.

As you cast instant and sorcery spells this turn, they gain “Draw a card” and “This spell deals 1 damage to any target.”

Tap any number of untapped creatures you control. You gain 4 life for each creature tapped this way.

{2}, {T}: Target opponent exiles a nonland, nontoken permanent they control.
{2}, {T}: Put target permanent card exiled with Harmony Array onto the battlefield under your control.

Whenever another nontoken permanent you control enters, create a Food token.
At the beginning of each end step, put X +1/+1 counters on up to one target creature, where X is the amount of life you've gained this turn.

Target creature an opponent controls loses all abilities and has base power and toughness 0/1 until end of turn.
Showcase {4}{U} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

First strike
Whenever you discard a card, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Ferocious — Whenever a creature with power 4 or greater you control enters, you gain 4 life.

Harpoon Launching deals 3 damage to any target. Create a 1/1 red Goblin creature token.

When Harpooned Bubbledomer enters, mill four cards.
Harpooned Bubbledomer gets +2/+0 and has menace as long as there are four or more card types among cards in your graveyard.

Reach
Whenever one or more creatures with flying attack, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Harpstring Ranger gets +2/+2 until end of turn. Untap it.

{1}, {T}, Move a -1/-1 counter from another creature onto Harried Apothecary: Each opponent loses 1 life and you gain that much life.

When Harried Submersible enters, target opponent creates a 1/1 blue Tentacle creature token.
Whenever Harried Submersible deals combat damage to a player or planeswalker, draw a card.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Flying
Harrier's Falcon can't attack or block alone.

First mate—Your starting deck contains at least twelve Vehicles. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Haste
{R}{W}, {T}: You may put a Vehicle card from your hand onto the battlefield. That Vehicle gains haste and becomes an artifact creature until end of turn.

As an additional cost to cast this spell, sacrifice a permanent.
When Harriet, Liberated Wildborn enters, you may remove all counters from target permanent.

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Wanderlust — When you cast this spell, you may copy it if you control four or more differently named lands. You may choose new targets for the copy.
Target creature you don't control gets -3/-3 until end of turn.

Target creature gets +3/-1 until end of turn.
Metamorph {1}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Sacrifice a creature: Harrowing Knight gets +2/+2 until end of turn.

Destroy target colorless nonbasic permanent. Harsh Erosion deals 2 damage to that permanent's controller.

Whenever an opponent activates an ability that isn't a mana ability, amass Soldiers 1 unless its controller pays {2}. (To amass Soldiers 1, put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create a 0/0 black Soldier Army creature token first.)