Firebolt is an ability that deals ability damage of a random interger between 1 and X to a random enemy, before the attack in the battle cycle of an unit. Obeying all the general laws of ability damage, it can trigger reflect, is blocked by immune, and cannot be blocked by physical defense.
Firebolt is irrelevant to burning status.
Firebolt All is exclusive to Flame Wave, and is equivalent to one Firebolt targeting each enemy in play. The damage of each firebolt is calculated seperately.