Flying
When Ryusei dies, it deals 5 damage to each creature without flying.

, : Another target creature you control gains flying and lifelink until end of turn.
At the beginning of your end step, if you gained life this turn, exile cards from the top of your library until you exile a nonland card. You may cast that card without paying its mana cost if the spell's mana value is less than or equal to the amount of life you gained this turn. Otherwise, put it into your hand.

: Note the name of target instant or sorcery card in your graveyard and put it onto the battlefield face down. It's a 3/3 creature with "Whenever this creature deals combat damage to a player, you may create a copy of the card with the noted name. You may cast the copy without paying its mana cost" and "If this creature would leave the battlefield, exile it instead of putting it anywhere else."

+2: Untap each enchanted permanent you control.
−1: Create a white Aura enchantment token named Mask attached to another target permanent. The token has enchant permanent and umbra armor.
−7: Mill seven cards. Return all non-Aura enchantment cards from your graveyard to the battlefield, then do the same for Aura cards.
Estrid, the Masked can be your commander.

Destroy all creatures.
Foretell (During your turn, you may pay and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

: Put a charge counter on this artifact.
, Remove three charge counters from this artifact: Destroy target permanent.

When this creature enters or leaves the battlefield, choose a land of each basic land type, then destroy those lands.

Flash
When this creature enters, if you cast it from your hand, choose target spell or ability that targets only a single permanent or player. Copy that spell or ability for each other permanent or player the spell or ability could target. Each copy targets a different one of those permanents and players.

Converge — You draw X cards and lose X life, where X is the number of colors of mana spent to cast this spell.

Create a 3/3 green Elephant creature token.
Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token gains haste until end of turn and attacks this combat if able.

When you cast this spell while you control your commander, copy this spell. You may choose a new target for the copy.
Return target permanent card from your graveyard to your hand.

Flying
Whenever Vorosh deals combat damage to a player, you may pay . If you do, put six +1/+1 counters on Vorosh.

, Exile two cards from your graveyard and this creature: Destroy target nonblack creature. It can't be regenerated.

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Destroy target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Kicker (You may pay an additional as you cast this spell.)
Burst Lightning deals 2 damage to any target. If this spell was kicked, it deals 4 damage instead.

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
When this creature enters, creatures you control gain double strike until end of turn.

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