Gained 2 levels on lvl up.
I have been two boxing a cleric and druid in a Brotherhood since the first quest at lvl 1.
I am currently at Camp Skawlra, I was fighting a lvl 19 Lumbering Dracoshell while both of my characters were at lvl 10. After the draco shell died both of my characters leveled up. My Cleric is now lvl 11, my druid is lvl 12.