While Caliban's Hand is equipped, killing with the explosion from prox. knife does not refund the melee energy. If you unequip Caliban's hand, an explosion from prox. knife will refund melee energy as supposed to. Video of this added.
Direct hit kills works fine.
Please let this be a bug and not intentional :(
Another issue; Caliban's Hand description says "Ignites targets on a direct hit" but it only ignites on direct hit kills.
-
And only if the knife gets the kill. If the explosion kills you get nothing. Pretty worthless exotic if not fixed.