Alex of the Blitzkrieg

Haste, First Strike, Trample
When Alex of the Blitzkrieg attacks, you may
pay {x}. If you do, Alex of the Blitzkrieg gets
+X/+0 until end of turn.
When Alex of the Blitzkrieg blocks, you may
pay {x}. If you do, Alex of the Blitzkrieg
gets +0/+X until end of turn.
The battle was won before midnight.