Oh, well. I posted it twice, si what's one more time
Crushing blow - 34 Xp
Treasure Searcher - 17 Xp
Ball of Lightning - 46 Xp
Mana Accelerator - 29 Xp
Mystic Egg - 44 Xp
Stone Wall - 39 Xp
Dragon Dive - 28 Xp
Fiery Phantoms - 37 Xp
Lava Call - 40 Xp
That's what you get at max level. Lower levels usually mean a few less xp points per level, but this table works for the lower skills as well - the skills that give the most XP at max level, do so too at lower levels.
As for that thingy... I think you simply started using the dragon less (or used his powerful abilities). For amelie to start overleveling the dragon, that means you started doing a lot of damage with your troops, rather that using the dragon at least once per round.