I had been attempting to make a spell which allows a hero unit to have his spells upgraded for a set time, the mechanism I intended to use was based on metamorphosis: the hero would use the spell to "transform" into an identical hero, but this one having the Engineering upgrade ability which upgraded 3 of his other spells. But I noticed that every time the time runs out the spells that have been learned before the metamorphosis spell had been activated all disappear leaving blank spaces. Does this usually occur or did I do something wrong? If this is typical is there another method of achieving the same result of having an ultimate spell that upgrades all of the other spells for a set period of time?