Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy.
Partner (You can have two commanders if both have partner.)

Magma Spray deals 2 damage to target creature. If that creature would die this turn, exile it instead.

Enchant creature
Enchanted creature gets +1/+3 and has reach. (It can block creatures with flying.)

Choose one —
• Mardu Charm deals 4 damage to target creature.
• Create two 1/1 white Warrior creature tokens. They gain first strike until end of turn.
• Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Target creature an opponent controls blocks this turn if able. Untap that creature. Other creatures that player controls can't block this turn.

Flying
Whenever a player sacrifices another permanent, put a +1/+1 counter on each creature you control.

Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)
, Discard a card: Merciless Eternal gets +2/+2 until end of turn.

You may exile a blue card from your hand rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Vigilance
: You may put a basic land card from your hand onto the battlefield.
: Return target basic land you control to its owner's hand.

This spell costs less to cast for each creature card in your graveyard.
: Monstrosity 5. This ability costs less to activate for each creature card in your graveyard. (If this creature isn't monstrous, put five +1/+1 counters on it and it becomes monstrous.)

Flash (You may cast this spell any time you could cast an instant.)
Defender (This creature can't attack.)
When Nivix Barrier enters the battlefield, target attacking creature gets -4/-0 until end of turn.

Inspired — Whenever Oreskos Sun Guide becomes untapped, you gain 2 life.

Flying

When Overgrowth Elemental enters the battlefield, put a +1/+1 counter on another target Elemental you control.
Whenever another creature you control dies, you gain 1 life. If that creature was an Elemental, put a +1/+1 counter on Overgrowth Elemental.

Flying
Whenever Pegasus Courser attacks, another target attacking creature gains flying until end of turn.

Target opponent reveals their hand. You choose a nonland card from it and exile that card.
Delirium — If there are four or more card types among cards in your graveyard, search that player's graveyard, hand, and library for any number of cards with the same name as the exiled card, exile those cards, then that player shuffles their library.

Sliver creatures you control get +1/+1.

Counter target spell. Its controller mills two cards.