Atomos

A monster that appears at the top of the Barrier Tower located in a faraway world. It guards one of the shield generators that protects the sinister dark mage Exdeath's castle. In another world, it makes use of the time magic, comet, and sucks in those who fall before it, after which it discards them in another dimension via a wormhole. It used the same techniques to torment Bartz and company.