Mirza, Spell Courier

{1}{u}{r}: Put Mirza, Spell Courier onto the stack.
It becomes a copy of target instant or sorcery
spell until it resolves, except it's a creature spell
in addition to its other types. Activate this ability
only once each turn.
Splice onto Creature {1}{u}{r} (Whenever a creature
enters the battlefield under your control, you may
reveal this card from your hand and pay its splice cost.
If you do, that creature gains this card's abilities until
end of turn.)