Kazuha, Acer Palmatum

Prowess

Whenever a Samurai you control attacks alone, you
may exert it and pay {1}{u}{r}{w}. If you do, until
end of turn, copy the next spell you cast that targets
only a single nonland permanent or player for each
other permanent or player the spell could target.
Each copy targets a different one of those
permanents and players.