[@Ryik]
1. Evolution lines would be linear with clear lines, like Gigobyte to Gagagigo. But for some monsters you can get creative, like Cloudian Smokeball could change into any of the other Cloudians before ending on Eye of the Typhoon.

2. You are allowed two.

3. Fusions will work as normal when having the necessary materials. But if the materials aren’t there, items can be found that correspond to the material you are missing. Like if you have Red-Eyes Black Dragon but want one of its fusions, you could have an item like a Meteor Fragment or a Daemon’s Skull.

4. Levels in general will be an indicator of the monster’s evolution level. And for the high attack Level 4 monsters, they’ll be sorta limited. Like if you wanted one, it’s power would have to be limited in some way before a certain point. Like the first dungeon clear.

5. As long as the ability would make sense for the monster and isn’t “random bullshit go! I win!” then that’ll work.