Avens, Sigiled Knight of Bant

Flying, exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone,
pay {x}{g}{w}{u}. Create X 1/1 white Bird Knight creature tokens with flying and exalted.
"A sigil is both a prize of honor and a bond of duty.
The one who bears it may be called to fulfill that charge at any moment."