Zion is a member of the second generation Seraphim in Paradox. She is said to be the most proficient at single combat of the second generation Seraphim.
Zion appears briefly in part 1, while Luka is on the way to Sentora.
A succubus intercepted the party in the place of Alma Elma when she realised they were navigating the ocean unimpeded, thanks to Poseidon's Bell.
Due to Alma Elma being otherwise occupied, she attacks Luka in her place to keep this world as close to the fundamental reality as possible. The reason she intercepts the party in Alma Elma's place is to slow the spread of chaos in this world.
She even handicaps herself to make it a fair fight, much like Alma Elma did.
However, unlike Alma Elma, Morrigan has no intention of being honourable in her defeat and prepares to unleash her full power.
When suddenly, a huge banner of Ilias unfurls above. An awful one, as Ilias herself points out. The wielder of the banner is Zion, one of the second generation seraphim.
However, she isn't here to rescue them. Zion has been hunting Morrigan for a long time and starts raining down holy light on the boat using her glove, with the intention of subduing Morrigan.
Morrigan is surprised that Zion herself would attack her in this world, and she warns her that killing Luka or any of the party members would spread the chaos, as they are only meant to interfere indirectly. Hypocritical of Morrigan, considering she had been prepared to turn them all into dried fish, no less than a minute ago.
Not that Zion cares, as she continues firing off more bullets of light on Morrigan, causing collateral damage to the boat in the process. She states that she will not compromise when it comes to annihilating Morrigan and her sisters.
Zion refusing to back down enrages Morrigan, and she takes flight, to battle with Zion.
Ilias warns Luka that if they don't jump off the sinking ship now, they will sink along with it. Luka thinks that it would be wiser to stay on the boat, but Ilias warns him that when a ship of this scale sinks, it will cause a huge whirlpool. They should get as far away from the boat as fast as possible.
As they jump off the boat, Zion and Morrigan prepare to clash with each other.