Tzeentch's Firestorm

Tzeentch’s Firestorm has a warp charge value of
6. If manifested, select one enemy unit within
18" of and visible to this PSYKER and roll nine
D6. For each roll of 6, that enemy unit suffers 1
mortal wound. If the result of the Psychic test
was an unmodified 9+, that enemy unit suffers
1 mortal wound for each roll of 5+ instead.