Hi, so sorry you are on this roller coaster. My son (3 at the time) was on Keppra - it did make him moody for sure and our doc said to use B6 and it really helped.
Many on this board use it with Keppra. He is now off the Keppra but on the Depakote and is OK with moodiness (well, he is 3.5 so the usual toddler moodiness exists). Check out the B6.