Flash
When Rhys enters, another target creature you control gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)
, : Remove any number of counters from target creature you control. Activate only as a sorcery.

Destroy target tapped creature.

Whenever you attack, up to one target attacking creature can't be blocked this turn. Return that creature to its owner's hand at the beginning of the next end step.
Choose a Background (You can have a Background as a second commander.)

Target creature gets -4/-0 until end of turn.
Investigate. (Create a Clue token. It's an artifact with ", Sacrifice this token: Draw a card.")

When this creature enters, you may cast target instant or sorcery card from a graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.
Encore (, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

This land enters tapped.
: Add .
Cycling (, Discard this card: Draw a card.)

Invoke Duplicity — Equipped creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may sacrifice Trickster's Talisman. If you do, create a token that's a copy of this creature."
Equip

At the beginning of your end step, if you control a creature with power 5 or greater, you may draw a card.
: Add .

Draw a card for each different mana value among nonland permanents you control.

This land enters tapped.
: Add or .

, Sacrifice this creature: Target opponent discards a card. Activate only as a sorcery.

Defender
This creature enters with four ice counters on it.
Whenever you cast an instant or sorcery spell, remove an ice counter from this creature. Then if it has no ice counters on it, transform it.

Flying, vigilance
Snow lands your opponents control enter tapped.
Noncreature spells your opponents cast with mana value 4 or greater cost more to cast.

Flying
When this creature enters, exile up to one other target creature or artifact you control. Return it to the battlefield under its owner's control at the beginning of the next end step.

Flying
You may look at the top card of your library any time.
At the beginning of each combat, you may reveal the top card of your library. If you reveal a creature card this way, this creature becomes a copy of that card until end of turn, except it has flying.

Channeled Dragonfire deals 2 damage to any target.
Harmonize (You may cast this card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by , where X is its power. Then exile this spell.)

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature's color.)
Flying

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

When this creature enters, create two Food tokens. (They're artifacts with ", , Sacrifice this token: You gain 3 life.")
Basic landcycling (, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Flash
Spells with flash you cast cost less to cast and can't be countered.