1) Does soldier's luck actually affect the chance of Hellfire working, or not?
2) Regarding the damage of the Exploding Corpses ability, here's a quote from the game: "When a dead unit is absorbed, a fiery explosion occurs, equivalent to casting the Fireball spell, but with a magic skill of 1 if an unupgraded unit is absorbed and a magic skill of 2 if an upgraded unit is absorbed."
So, does this mean that when absorbing an upgraded corpse, a double Fireball is cast? Or is it simply that a Fireball with 20 + 20*2 = 60 damage is cast for an upgraded unit, and a Fireball with 20 + 20*1 = 40 damage is cast for an unupgraded unit?
If it's the second option, then the ability isn't that useful. And by the way, does it affect friendly units?