For those who liked the way it ended, with Herobrine being spared: You don't need to read this chapter :)
For those who don't care and/or want to see both endings, and for those who want to see Herobrine killed: here you go ^_^
Warnings: Major character death, blood, gore
~3rd P.O.V.~
(Taking place as the beginning of chapter 38)
Preston pauses for a second, registering Herobrine's statement. Pfft. As if Herobrine's actually sorry. He decides, shaking his head, and bringing the sword down. The sword swings down at full force, but before it can split Herobrine's skull, an afterthought hits Preston. So he stops, the blade halting within inches of his hair.
"Hold on..." Preston pauses, "I wanna try something before I can't do it again. And because you don't deserve a quick death."
Preston steps back, putting away his sword. Instead, with a satisfied yet angry expression, begins to morph. His form expands, and it keeps growing until it's about half the size of a ghast, and then begins to take shape. A head, two arm-neck like things, two smaller heads in place of the hands, and a long ribcage that diminishes into a short tail. Preston has turned into a lava wither.
Preston let's out a ghastly scream, stretching out his joints. Then with a glare, he shoots two successive wither skulls, both glowing orange. Herobrine shrieks as one strikes him directly, followed quickly by another, sending him flying back a few blocks. The moment he hits the ground, the wither affect quickly kicks in, forcing him to scream bloody murder at the searing sensation spreading throughout him. As Herobrine withers around on the ground, unexplainable aim engulfing and paralyzingly him, Preston floats closer with a smirk.
"Preston, wait." Rob calls uncertainly, whereas the others watch on with blank expressions.
"Yea?" Preston replies, turning to where Rob has stepped up beside him. His aura is still flaring, but it's died down a bit now.
"Are you sure you should be doing this? I mean what if he really is sorry?"
Preston regards the possibility for a moment, then shakes his head.
"Rob, do you seriously think Herobrine's sorry? He's probably just trying to trick us, get us guilty and get you to heal him, and then attack us while our defences are down."
"Yeah.. Okay... I guess you're right." Rob agrees uneasily, stepping back with the others.
"Now where was I?" Preston smirks, floating closer still the the quivering form in the ground.
The wither effect has worn out by now, but Herobrine is too weak and injured to move, or even lift his head. The only thing he can do if follow Preston with his eyes, watching miserably as his terrifying wither form towers above him, casting a shadow over his broken form.
"P-please..." He manages to squeeze out, the message speaking for itself even with just one word.
"Hmm... Let me think about that." Preston fakes, rolling his eyes, then he leans close to Herobrine's ear. "You should've thought of that sooner, buddy."
And with that Preston let's out one last wither blast, which at such close quarters, completely obliterates Herobrine. His mangled form skids back, a ring of items creating a trail as he slides, before finally coming to a stop.
"Good riddance."
~~~
Epilouge and after story are coming soon, and the Epilogue should be up tomorrow :)