Yeah, after some consideration, I figured to continue this story as best I was able. And by 'best I was able', I mean a one-shot series since that's apparently all I'm good for these days, hm?
Everyone, Green, Red, Blue and Orange Lantern, Star Sapphires, Indigo Tribe Members, Sinestro Corpsmen, Black Lanterns, and fighting heroes alike paused when a space-time rift opened up on the battlefield. Indeed, even Nekron and the Entity seemed surprised, even shocked, when someone emerged from within it.
Saint Walker briefly noted the resemblance of her attire to that of a Red Lantern. The suit itself seemed entirely black, with scattered bits of scarlet armor on her body, including on her shoulders, forearms, and everything below her waist, though he decided it unlikely for her to be one, as she lacked the crimson aura, a visible ring. It wasn't until then he noticed her unusual appearance.
Her eyeballs were emerald-green, smoldering and pulsating with strange energies, and her body was incredibly lithe; even extreme malnourishment shouldn't allow such a lanky build, he decided, so how she had one such, was beyond him.
As if responding to her arrival, the ring of a falled Red Lantern flew from his hand, zigzagging on it's path towards her. "Xadhoom of Xerba, you have held great rage in your heart," The ring whirred, placing itself on a bewildered Xadhoom's finger. She noted it to be similar to the trinket the green-and-black clad man wore. "You belong to the Red Lantern Corps."
Saint Walker and Hal watched in horror, as the crimson aura flared around her, the Red Lantern insignia appearing in her eyes, her attire remaining unchanged. They were surprised when she didn't vomit up any blood as literally every other inductee did, and even more so when she calmly removed the ring from her finger, none-the-worse-for-wear.
"I belong to no-one, little thing," She drawled, tossing it aside, before noticing another of those rotting corpses. They had walking dead here? She never had finished that fight with Alucard...
"Oh great," She smirked. "I haven't killed undead things in centuries!" Hal and Walker blinked at this; zombies weren't a big deal for the veteran GL, but centuries? The newcomer was immortal? They didn't have long to ponder the matter, as she went for several Black Lanterns, fighting with a ferocity that almost matched that of a Red Lantern, flinging energy-blasts at them, cutting off body parts, a head here, an arm there, and occasionally a leg as well, only for them to regenerate effortlessly, due to whatever power she used not being a part of the Emotional Electromagnetic Spectrum.
"Remarkable..." Saint Walker whispered in awe, watching her tear through hordes of Black Lanterns, seemingly relishing the opportunity to cut loose. To Xadhoom's annoyance, these dead things just wouldn't stay down.
Hal and Carol froze when a Black Lantern plunged it's hand into her chest. The Star Sapphire attributed her lack of reaction to sheer shock at the grievous injury, surprising her greatly when the wild-haired blonde smirked wider than before.
"Sorry," She sneered at the offending Black Lantern, tearing its arm off. "But it takes more much than that to kill me!" She shouted, her hands crackling with energy, discharging an enormous energy-blast engulfing the Black Lantern entirely, obliterating it utterly. Saint Walker gaped at the sight, shocked when the Black Lantern didn't regenerate; according to what the Indigo Tribeswoman had told them, it took two or more shades of emotional light to put a Black Lantern to rest, yet she had done it with only a single variety of energy.
"That wasn't so difficult," She grinned to the other living humans present, a bit drained from the exertion of so much power at once. Saint Walker stared at her, disturbed by her complete disregard for the should-have-been-fatal injury; just what sort of otherworldly creature was she?
"Anyone care to tell me how to kill those things for good?" She sardonically asked to the incredulous ring-wielders, her eyes narrowing in disbelief and curiosity when she sensed the energies within those rings.
It felt like standard-fare light, fire and electricity, but at the same time, it also felt like more than just energy, like it was... Xadhoom had no idea how to describe it, but it felt vaguely alive somehow.
"Doesn't that hurt?" Hal asked, shaken by the sight. In his years as a Green Lantern, he'd seen nearly everything imaginable but this... This was something else; not even Superman or the Guardians could possibly survive an injury like that, and definitely not shrug it off as nothing, no metahuman on earth could. Not even Beast Boy or Animal Man with their amorphous physiologies could.
"What, this?" Xadhoom replied, smirking, pointing a finger to her mangled chest cavity. "No, I'm fine."
"Oh Jesus, I'm going to be sick!" Carol groaned in disgust. Saint Walker supposed that it was understandable. whoever Jesus were. The internal anatomy, of any species, was rarely a pretty sight.
"Really, physical injuries like this can't really hurt me," Xadhoom revealed to the incredulous group.
"It would take the powers of our rings to put a Black Lantern to rest," Saint Walker told her, still unsure of what exactly was going on. The reanimated dead, he could somewhat cope with, seeing someone who was evidently alive survive wounds that should not, could not, be survivable... Just what manner of creature was she? It was unreal! Even Earth's residents, for all their incredible and diverse powers, were still mortals, and even immortals like the Guardians would succumb to wounds like this. "What... Are you?" Walker whispered, horrified and shocked.
Her grin widened at the question. "I am Xadhoom. That is all you need to know." It was then that she noticed the larger corpse, lacking a black ring, and wielding a scythe.
"Excuse me for a moment," She smirked, beginning to walk towards the larger undead, her hands surrounded by flame-like, crackling, pulsating, undulating energies. She was stopped by a large emerald-green hand appearing in front of her.
"We can't let you," Hal spoke. "Not even the Spectre or the Anti-Monitor could lay a finger on Nekron, and I strongly doubt that you can."
"The who and the who?" Xadhoom and Saint Walker quizzically asked. Now that the Blue Lantern thought about it, Hal had expressed some familiarity with both of those entities, but how exactly he knew of them was a mystery to him.
"First, does either of your homeplanets have any sort of religions?" Hal slowly asked the two, who blinked at the question, wondering how religion was relevant. Xadhoom responded in the negative while Walker responded in the positive. "Well, the Spectre is the vengeance aspect of an earthly creator god, and from what I've been told, the Anti-Monitor is a being from the anti-matter universe who several years ago invaded the positive-matter multiverse, forcing the merging of all parallel realities, leaving only his own and ours in existence." Hal finished to the more-than-slightly-skeptical Xadhoom and Walker.
"I am sorry, Hal, but I honestly find that hard to believe," Saint Walker stifled a laugh.
"As do I, considering that I'm from a parallel reality, and have seen several others." Xadhoom chuckled, bewildering Hal sufficiently that his construct flickered and faded. "Now, you stay put, and I'll dispense of this 'Nekron'..."
Before anyone could stop her, she was already confronting the dark god himself. "Strange..." Black Hand noted, watching the newcomer's futile struggle with his master. Like the Stranger, she was something not quite dead, but not quite alive, though her power was similar to that of a Lantern, wild, destructive and forceful, yet she wore no ring, and her emotional aura shone with green light as well as red...
"What are you?" Nekron's guttural hiss demanded. "You are from beyond the fifty-two, and you are unlike the living beings of this universe, yet you are somehow both alive and dead..."
"What of it, Nekron?" Xadhoom shot back, uncertain what 'the fifty-two' referred to.
Nearby, the Entity watched her fight his opposite number. Though it was apparent that her power was great, against Nekron, simply that would not suffice, leaving the Entity with but a single course of action. Though she wasn't the best choice of host, she would prove more suitable than the Guardians, Sinestro or Hal Jordan. With her seemingly limitless, self-replenishing power to fuel the limited though vast supply of White Light the Entity wielded, she was the best choice presently available.
Xadhoom and Nekron were both too distracted by their fight to notice the Entity fly at her, and merge with her.
Slowly, the scarlet portions of her suit turned clear white while the black portions turned soft-gray, and her entire body shone with white light, the emerald color of her eyes shifting to white, blazing brighter than ever before.
"NO!" Nekron screamed, as his Black Lanterns began to amass on the newly-minted avatar of life itself. "I WON'T ALLOW IT!"
"Oh, is that so?"The merged entity smirked, raising her right hand, ready to snap her fingers. "You don't have a choice!" They declared, snapping her fingers. Around them, almost all the Black Lanterns erupted with blazing white light, returning the dead to their rest. "Now return to your own realm, Lord of the Unliving!" They demanded, and Nekron's corroded flesh ignited with the same light.
"Never!" He screamed, as the light faded. "I will not allow you to disrupt the order of my universe!"
"As you wish," The Entity declared from within Xadhoom, and they turned to Black Hand. "William Hand of Earth, Live!" The white light washed over him, his skin becoming healthy, his flesh, muscles and bones repairing, his Black Lantern Ring crumbling, as Nekron did, with the lack of a tether. Their task completed, the Entity and its host separated, leaving a thoroughly exhausted Xadhoom where a White Lantern had stood.
To Hal's surprise, she was breathing heavily. "What are you..." Xadhoom drawled slowly to the Entity. "And how much energy did you take just now?"
"I am the Entity embodying Life itself, on the universal scale," Xadhoom was succinctly informed, much as she doubted the concept due to it being utterly ridiculous. "And I siphoned no more than you could readily spare, enough to replenish what I have lost, from the wounds Nekron inflicted on me, resurrecting Black Hand and your slaughter of the Black Lanterns."
"True," Xadhoom shrugged, and turned to leave, leaving a bunch of highly confused superheroes and ringwielders in her wake.
Yeah, this ended as about as well as it could. To anyone unfamiliar with Xadhoom, she was a extraterrestrial astrophysicist, who performed an experiment on herself, making her a star in humanoid form, giving her a wide range of powers; she's functionally equal to a Lantern in power, and with the ring... We would be looking at a ring-wielder/emotional entity combination-equivalent here.
And a few notes, detailing events of possible controversy.
1) As for how Xadhoom could casually remove the ring, well that's because she lacks internal organs and a circulatory system. It's all mass and energy in there, making her perfect for Black-Lantern ass-kicking.
Come to think, this thing becomes hella funny, considering Guy's comment about Walt Disney puking up a rainbow across the universe. No? Okay...
2) As for how she was more effective against Nekron than the Spectre, the spirit of God's vengeance, that's because she delivered a direct assault like the Anti-Monitor, rather than judge his (non-existant) soul.