Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, add that much . Until end of turn, you don't lose this mana as steps and phases end."

Enchant creature
You control enchanted creature.
At the beginning of the end step, if you control no Demons, sacrifice Mark of the Oni.

: Matsu-Tribe Sniper deals 1 damage to target creature with flying.
Whenever Matsu-Tribe Sniper deals damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Prevent the next 4 damage that would be dealt to any target this turn.

, : Target creature with power X or less can't be blocked this turn.

Counter target spell. That spell's controller reveals their hand, then discards each card with the same name as a card spliced onto that spell.

The "legend rule" doesn't apply.

Ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Mistblade Shinobi deals combat damage to a player, you may return target creature that player controls to its owner's hand.

Sacrifice Moonlit Strider: Target creature you control gains protection from the color of your choice until end of turn.
Soulshift 3 (When this creature dies, you may return target Spirit card with converted mana cost 3 or less from your graveyard to your hand.)

Whenever equipped creature deals damage to a creature, tap that creature. That creature doesn't untap during its controller's untap step for as long as Neko-Te remains on the battlefield.
Whenever equipped creature deals damage to a player, that player loses 1 life.
Equip

Sacrifice Nezumi Shadow-Watcher: Destroy target Ninja.

Ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Ninja of the Deep Hours deals combat damage to a player, you may draw a card.

You may exile a green card with converted mana cost X from your hand rather than pay this spell's mana cost.
You gain X life.

Whenever Ogre Marauder attacks, it gains "Ogre Marauder can't be blocked" until end of turn unless defending player sacrifices a creature.

Whenever a player casts a spell, tap Ogre Recluse.

Ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

Defender (This creature can't attack.)
Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
: The next time a source of your choice would deal damage this turn, that damage is dealt to Opal-Eye, Konda's Yojimbo instead.
: Prevent the next 1 damage that would be dealt to Opal-Eye this turn.

Permanents enter the battlefield tapped.

, : Target opponent exiles the top card of their library. You may play that card this turn.

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.
Splice onto Arcane (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)