STAB + psychic terrain makes psyshock essentially base 180, and psychic base 202.5, both greater than super effective shadow ball (160). Shadow ball is redundant, unless you want it to hit Aegislash harder than hp fire does.
Both Aegislash and Alolan Marowak take fuck all from HP Fire, and I already specified that. There's nothing relevant that's going to get lured or revenge killed by HP Fire as even the more idiotic Scizor player knows to cut losses and switch out against Tapu Lele.