Challenge you to a Duel

This spell can't be countered.
Target creature you control fights target creature
you don't control.
"I know what you did that day Walker. I know it
was you who killed Marcus an Claire. You left
their little girl to die! Alone! Just to be Captain!
I challenge you for the title! You best hope I cut
you down here, an that little girl doesn't grow up
and learn of you." Lieutenant Mildred