Rapturous Standard

Use this Stratagem before the battle.
Choose one of your SLAANESH models with a
Daemonic Icon.
That icon is upgraded to a Rapturous Standard.
In addition to its normal ability, the power of the
banner can be used once per battle, just before
the bearer's unit fights. When used, you can
re-roll all failed hit rolls made for the bearer's
unit untilend of the phase.