Elysion is a new unit introduced in Metal Slug Attack.
A pirate from the past, Elysion was one of "average" traits - despite this, she eventually became so skilled that she was able to avoid the authorities for years. Her greed eventually overwhelmed her, and she started to indiscriminately attack both boats and ports. Eventually, all traces of her were removed a "black sailboat". The remains of both her and her crew were washed ashore onto a nearby island, which was then enveloped in fog. Ships that approached the island were sunk to the bottom of the sea, giving it the nickname "Cursed Island". Rumors also spread about her great treasure that was hidden on the island.
The curse revived both her and her crew, though they were limited to the island. Though initially horrified, she eventually realizes her greed became her undoing and vows to return to the sea once more. However, in her initial appearance, the curse came from Monoeye UFO, which is not mentioned in Another Story.
She enjoys drinking wine, as shown in her victory sprites.
First appearing in the Extra Ops "Clash of the Worlds", she finds herself mutated and searches for the Monoeye UFO to destroy it. Upon discovering the Monoeye UFO, she summons three krakens to penetrate the glass dome, destroying it.
First appearing in "Little Song", Elysion and her crew are reanimated by the seal being broken by Aileen and her pirates. She initially repels a Martian attack, though she is still able to sense more living beings and sends out the local wildlife to deal with them. Aileen and her pirates soon battle Elysion and her crew. Elysion is disappointed by the path Aileen follows, as it was the one she had done centuries ago. The Ghost Shiee eventually arrives as backup, but is destroyed by Halle and Mars People Pocket, causing her to fade away with her supposed treasure.
- Her death animation is similar to that of several Invaders.
- Elysion is the first unit in Metal Slug Attack to change dialogue when the special attack is enhanced, changing from "Kraken!" to "Burn them!". This trait is also seen when Elena and Licht's special attacks are enhanced.
- Though initially appearing in "Clash of the Worlds", she did not make any other appearances until the release of the story "Little Song". The story also gave her dialogue.