I defeated Zulrah and did not receive all the loot I was supposed to get. According the this link, It says I was supposed to get a an elytra and ancient key but I did not receive those items. I have heard this happened before but I did not know what the outcome was.
So I'm pretty new to the server but I do know you that you'r "EXP" level which you can use to enchant. The "XP" is for your server level, which stays with you no matter what sub-server your on. I don't know the purpose of it, I guess it's just a cool stat people like to look at. Just by playing...