Undying.

Undyne managed to jump in front of Monster Kid just in time to take the hit, the slash somehow managing to pierce through her armor, almost cutting her in half. ". . ." She had a... strange expression, until MK said she was hurt. "..." She then smirekd and glanced down at Monster Kid. "... Hurt..? Hah... It's nothin'... Next time I tell you to listen.. do it." As MK tried to say something, she interrupted him. "Go! I can take care of this!" .... MK slowly walked away. Undyne's expression slowly darkened, as her body's form started to waver. "..... H-Heh... 'It's nothing'..... No-.." She slowly fell to her knees. "... Somehow... with just one hit... I'm already.." She set her hand on the slash across her chest. "... Already......" She growled softly and slammed her fist on the ground. "D-... Dammit......." Her expression faded into sadness, her eyes closing. "... P-Papyrus..... A-Alphys.... A-Asgore...... Just.. like that.... I- ... I've failed you..." Her body then slowly started to fade into dust...... however, halfway through doing so, the dust particles started coming back together, her body slowly reforming. ".... No." She continued to stay kneeling, raising her head slightly to speak towards the human. "... My body.... It feels like it's splitting apart.... Like any instant... I'll scatter into a million pieces." She started to slowly stand up. "...But deep... deep in my SOUL... There's a burning feeling I can't describe.." She then opened her eye, her pupil glowing white and her eye dark. "... A burning feeling.. that WON'T let me die..." Her hair slowly swayed in the wind. "... This isn't just about monsters anymore... Is it? ... If you get past me, you'll destroy them ALL, won't you?" She slowly started taking small steps towards the human. ".. Monsters... Humans... EVERYONE..." She held her arms by her sides, stopping her movements. "... Everyone's hopes... Everyone's dreams..., vanquished in an instant. But I WON'T let you do that.." She then grinned. ".. Everyone in the world.." She set her hand on the slash once more. "... I can feel their hearts beating as ONE... And we all have the same goal.." She then pointed at the human. "To defeat YOU." Her arm lowered to her side. "... Human- No....... Whatever you are...  For the sake of the whole world.... I.... UNDYNE... will STRIKE YOU DOWN!!" She pointed upwards, her form wavering rapidly, before a bright light covered the area. ... As the light faded, Undyne's form had changed. Her armor a dark purple, the eye that had the eyepatch emitting a ray of light that rose and fell. She stood there, her eyes closed, grinning, before bringing her arm out and summoning her large spear, pointing it towards the human. She opened her eyes, staring right at them. "You're gonna have to try a little harder than THAT." * The heroine appears.