What types of items or creatures there will be?
Initially we thought only about creatures that you can have during the fight with you. Having additional items like helmets or other body protection also makes sense. But creatures sounds more fun at least during discussion.
Will you guys allow items from other games to be used inside your game?
We know that there are examples of that like crypto kitties are using in cat fight. We might consider it if the community will ask for that.
How will the experience grow and affect stats or fight process?
Creatures can add points to your stats, skills of your hits and avoid probability. That can be adjusted on different servers so some things have less or more effect.