I decided to give my level five character my Ancient Death Leprechaun that has life gift and mana gift. I decided that a new storm wizard could really use the extra hundred life and mana. Now, when the storm wizard took the leprechaun out of the bank his pet energy dropped to zero as expected: but then, a little later he leveled up and his pet energy fully refilled! Of course he couldn't do any training as he wasn't allowed into the pavilion. It's just that I didn't notice this feature on my level 30ish necromancer because he levels up so infrequently. If you happen to have a level seven character, you should probably pass him your pet that you are trying to raise. After all, lower level characters level up faster so you would have more free energy recharges. You would need to have that character buy snacks though. I just found out that snacks cannot be put into the shared bank.