Amulet Strike is safest non variation, non ex, non mb Shinnok's special.
f224 is -17 on block, Amulet makes it -10, if you don't have meter to mb Hell Sparks.
exAmulet is +14 on block with better than HS1mb positioning, but with less chip. It have less damage scaling and it launches on hit, so you can do quite damaging combos in the corner with it.
Other than situational combos Amulet Strike is inferior to Hell Sparks. I hope NRS will decide to add Armor Break on exAmulet Strike, so it becomes a bit more useful.
Hail to the "most potent and powerful of all mystic talismans within all the realms."