Fiend's Grip is supposed to deal 5 (7 with Scepter) damage instances, starting immediately on cast, then once per second.

However, depending on your player slot and the target's player slot, it deals 6 (8) instances of damage.

If Bane is blue, teal, purple, yellow, orange, pink, olive or brown, Fiend's Grip deals 6 (8) against light blue and dark green, but 5 (7) against all other slots

If Bane is light blue or dark green, Fiend's Grip deals 5 (7) against all other slots, but 6 (8) against light blue and dark green (but since they are always allied, they effectively deal 5/7 damage instances)

It should always deal 5 (7) instances regardless of player slot.