This loops in the Effekseer editor (sort of; you can see the animation flicker between the ending and beginning of the loop for a split second), but not the MZ editor. MZ plays the end of the animation, which breaks the loop.
Actually, I have one I found online that does loop in the MZ editor. I've left it playing for minutes at a time just to see if it looped infinitely, and unless it's set to run for an excessively long amount of time, pretty sure it actually loops without any input after hitting the play button in the editor. I tried to replicate its settings in the Effekseer editor with your aura animations as best I could, and it didn't work. The looping one isn't based on a sprite sheet, so there might be something the typical MZ animations can do which sprite sheet animations can't. Regardless, animations looping while playing in the editor is possible, so I figured I'd ask about it.