msem-instigator

Draw three cards, then reveal your hand.

When Over the Horizon enters, scry 1.
{T}: Add {C}.
{1}, {T}: Return Over the Horizon to its owner's hand.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
Over the Moon deals 4 damage to up to one target creature or planeswalker.
Until end of turn, spells you cast with mana value 4 or greater cost {1} less to cast and can't be countered.

Hexproof
When Overburdened Trader enters, create three 1/1 colorless Construct artifact creature tokens.

Counter target spell. For each other card named Overcharge in your graveyard, create a colorless Canister artifact token with “{T}, Sacrifice this artifact: Add {C}.”

Kicker—Sacrifice an artifact or creature. (You may sacrifice an artifact or creature in addition to any other costs as you cast this spell.)
Choose target creature you control. Put a +1/+1 counter on it if this spell was kicked. Then it deals damage equal to its power to target creature you don't control.

Destroy target creature with power 4 or greater. (You need a target to cast this spell.)
Tap up to two target creatures.

When Overconfident Batter dies, if it's enchanted or you cast a spell that targeted it this turn, you gain 3 life.

Until end of turn, creatures you control have base power X/Y, where X is the greatest base power among creatures you control and Y is the greatest base toughness among creatures you control.
If you control a creature with flying, creatures you control gain flying until end of turn. The same is true for first strike, haste, lifelink, menace, prowess, trample, and vigilance.

Any number of target players each draw seven cards, then discard seven cards.

Target creature gets +2/+1 and gains haste until end of turn.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Target player reveals their hand. You choose a nonland card from it. That player discards that card unless they discard three other cards.

{G}, Tap an untapped Nymph you control: Overgrown Beast gets +2/+2 until end of turn.

Overgrown Enclave enters tapped.
{T}: Add {G} or {U}.
{4}{G}{U}: Until end of turn, Overgrown Enclave becomes a Turtle creature with ward {2} in addition to its other types.
Scavenge {5}{G}{U}

{T}, Pay 1 life: Add {G} or {W}.
{1}, {T}, Sacrifice Overgrown Refuge: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Overgrown Ruins enters tapped.
As Overgrown Ruins enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Overgrown Siren must be blocked if able.

Trample
Overgrown Spellroot gets +1/+1 for each creature token you control.
When Overgrown Spellroot enters, create four 1/1 black Worm creature tokens.

Whenever Overgrowth Host attacks, germinate. Then creatures you control that are Saprolings or have counters on them gain trample until end of turn.
Saprolings you control get +1/+1.

This spell can't be countered.
Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Haste (This creature can attack and {T} as soon as it comes under your control.)

Each player discards two cards. Then if there are four or more card types among cards in your graveyard, create two 1/1 white Human creature tokens.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Overheat deals X damage to any target.

Overkill deals 4 damage to any target that was dealt damage this turn.

{T}: Add {C}.
{7}, {T}: Copy target instant or sorcery spell with {X} in its mana cost. You may choose new targets for the copy. This ability costs {1} less to activate for each instant and sorcery card in your graveyard.

Recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)
Target creature you control fights target creature you don't control.