Leviathan will reflect ranged attacks. D:

[Tarushade]

If this reflect buff is anything like coil's turn 4 soldiers, the damage is reflected back onto the user of the attack, no one else. So no troll killing party, just trollin' yerself. In the case of aoes it seems it's still just reflected back at you.

Which in turn trolls the party b/c endgame EX primal deaths normally affect the outcome of the battle even if only 1 person dies.