You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Echo (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When The Keeper of Four Scythes enters, create four Scythe tokens. (They're Equipment with "Equipped creature gets +1/+1" and equip .)
Equipped creatures you control get +1/+1.

Enchant Wall
Enchanted Wall can attack as though it didn't have defender.

Reveal the cards in your library. An opponent chooses from among them a creature card, a land card, and a noncreature, nonland card. You put the chosen cards into your hand. Then shuffle.

Flying
Whenever this creature blocks or becomes blocked by a non-Wall creature, destroy that creature at end of combat.

Counter target activated ability. (Mana abilities can't be targeted.)
Draw a card.

Creatures get -X/-X until end of turn, where X is your highest commander tax among your commanders. (For example, if you've cast your one commander from your command zone twice, creatures get -4/-4 until end of turn.)

Flash
Flying
Ebondeath enters tapped.
You may cast this card from your graveyard if a creature not named Ebondeath, Dracolich died this turn.

Destroy target creature with mana value 3 or less. It can't be regenerated.

All lands become 2/2 creatures until end of turn. They're still lands.

Equipped creature has double strike.
Whenever equipped creature attacks, if it's the first combat phase of the turn, untap it. After this phase, there is an additional combat phase.
Equip

Target creature gains hexproof and indestructible until end of turn. That creature is 1/1 until end of turn and can't be anything other than 1/1 until end of turn. (No matter what happens to it, it'll still be a 1/1.)

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

You gain 3 life. Draw three cards. Add . This spell deals 3 damage to any target. Target creature gets +3/+3 until end of turn.

Nonlegendary artifact creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

At the beginning of your upkeep, you gain 2 life for each Shrine you control.

Choose an artist other than Rebecca Guay. Target player reveals their hand and discards all nonland cards with art by the chosen artist.

Reach, lifelink
One for My Baby — Whenever you attack with two or more creatures, put two quest counters on Craig Boone. When you do, Craig Boone deals damage equal to the number of quest counters on it to up to one target creature unless that creature's controller has Craig Boone deal that much damage to them.

Amass Oozes X, where X is the number of creature types among creatures on the battlefield. Don't count changelings. That would be ridiculous. (To amass Oozes X, put X +1/+1 counters on an Army you control. It's also an Ooze. If you don't control an Army, create a 0/0 black Ooze Army creature token first.)