Deathmask Nezumi

Reveal your hand: If you have seven or more land cards in your hand, flip Sasaya.

Flying Whenever you cast a Spirit or Arcane spell, destroy all permanents with that spell's mana value.

As long as you have more cards in hand than each opponent, this creature gets +3/+3.

Soulshift 5 (When this creature dies, you may return target Spirit card with mana value 5 or less from your graveyard to your hand.)

Counter target spell unless its controller pays 1 for each card in your hand.

Discard your hand.

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)

(Nonexistent mana costs can't be paid.) Draw a card. Splice onto Arcane 1U (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.)