As an additional cost to cast this spell, you may sacrifice any number of artifacts and/or creatures. This spell costs less to cast for each permanent sacrificed this way and less to cast for each other artifact or creature you've sacrificed this turn.
Trample
Partner (You can have two commanders if both have partner.)

: Each player may draw a card, then each player who drew a card this way gains 1 life.

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Flying, haste
When Karrthus enters, gain control of all Dragons, then untap all Dragons.
Other Dragon creatures you control have haste.

Other Elf creatures get +1/+1 and have forestwalk. (They can't be blocked as long as defending player controls a Forest.)

: Add one mana of any color.
, : Create X 1/1 white Soldier creature tokens, where X is the number of Bobbleheads you control. Activate only as a sorcery.

Prevent all combat damage that would be dealt to and dealt by creatures you control.

Tap another untapped creature you control: Tyvar gains indestructible until end of turn. Tap it.
: Creatures you control get +X/+X until end of turn, where X is the greatest power among creatures you control.

Whenever a Wolf or Werewolf you control deals combat damage to a player, draw a card.
At the beginning of your upkeep, if you control three or more Wolves and/or Werewolves, it becomes night. Then transform any number of Human Werewolves you control.
Daybound

All creatures gain hexproof and indestructible until end of turn. Players gain hexproof until end of turn. Players can't lose life this turn and players can't lose the game or win the game this turn.

Whenever you cast an artifact, instant, or sorcery spell, copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.)
Whenever an opponent casts an artifact, instant, or sorcery spell, counter that spell. This ability triggers only once each turn.

: Add one mana of any type that a land you control could produce.

Trample
When Bumi enters, earthbend 4.
Whenever Bumi deals combat damage to a player, untap all lands you control. After this phase, there is an additional combat phase. Only land creatures can attack during that combat phase.

As Chronicle of Victory enters, choose a creature type.
Creatures you control of the chosen type get +2/+2 and have first strike and trample.
Whenever you cast a spell of the chosen type, draw a card.

Whenever Karn blocks or becomes blocked, it gets -4/+4 until end of turn.
: Target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value until end of turn.

This land enters tapped unless you have two or more opponents.
: Add or .

You may exile a black card from your hand rather than pay this spell's mana cost.
Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
You may have this creature enter as a copy of any creature on the battlefield, except it's a Ninja in addition to its other creature types.

Whenever an opponent casts a spell, reveal the top card of your library. If it's a creature card, put it onto the battlefield. Otherwise, you may put that card on the bottom of your library.

: Add .
: Add or . Activate only if you control a Swamp.