Sprint or Marathon

Chose a color, then chose:
•All creatures you control of the chosen color
gain first strike until end of turn. All creatures
you control of the chosen color who have last
strike don't have it until end of turn.
•If you play this sorcery in your first main phase,
all creatures you control of the chosen color have indestructible until the end of your next combat
phase.
"First blood is mine. Mine!"
—Spinning Dancer, acrobatic duelist