Tip: The Paladin's Holy Shield carries on even if you change heroes, so if you grab the paladin, and then a mage, you will have a mage with a holy shield
A tip to gain lots of exp early on: Do one of the kitchen levels, and keep running around as many rocket/venom towers as possible. You will kill everything, and you are able to hit about 10 levels the first time
I just wanna know if there's a monster guide so that you know what you are getting before you get one and replace those on your team. I mean like, it helps with that "exploring of monsters to pick your favorite", but in my opinion i would like to be prepared