Atomos (Final Fantasy)

Atomos is an optional boss in the Dawn of Souls and 20th Anniversary versions of the original Final Fantasy, who can be fought in the Lifespring Grotto. It has a sprite similar to its Final Fantasy V counterpart, with greater detail.

Strategy
Atomos has a very annoying Wormhole attack, which automatically KOs one of your characters. NulBlaze would work well to protect against Firaga and Protera can make Atomos's already weak physical attack even weaker. Try to kill off Atomos as quickly as possible to avoid Wormhole hitting too many times. The faster you shave off his precious HP, the better chance you'll have of winning the battle without most of your team dead. As with most bosses in the game, casting Saber (with the Giant's Gloves) and Haste on the physical units is going to make the battle a whole lot easier since most bosses have more resistance to magic than to physical damage.