GOOD NEWS GUYS. I've been checking the boards of the avatar simulator via Google Translate lately and looking around. I found a link to a different simulator that was also down, I checked the boards and many of them were posting to getting it fixed.
NOW THE GOOD NEWS IS?
IT'S (temporarily) FIXED!
arad avatar simulator
Click the top link, then it functions just like any other avatar simulator.
The major changes, according to Google Translate again, is that you only have one pose and there are some bugs, but it was very vague on the latter part.
Now I can see how my Nen Master and Battle Mage will look. QQ