#i also really like the idea it just dones't work

[surelysilly]

Okay but cas killing phanuel and later finding out he wasnt dangerous, evil or harmful >:)

so, actually, there are three ways it could go, because to have Castiel 'kill' Phanuel, this would need to be early season Cas... stab first, ask questions later:

Phanuel's Grace is that of a Archangel, and arguably, the angel blade won't work. Castiel just stabs this undeniable abomination and it doesn't die. Phanuel is traumatized because it hurts, but no more dead than usual.

or,

Phaneul's Grace is weak enough it... works, for lack of a better term. The grace dies, but the ectoplasm saves the human soul. Suddenly the Danny Phanton theme song starts playing lol (jk) but we have a brand new, uh, weird looking halfa and the town is overrun by ghosts more so than canon, because most ghosts are freaked out by Phanuel and want nothing to do with them. But now without the Grace, what's to be afraid of. Castiel left before he sees any of that. He maybe regrets it later, once he's had a bit more exposure to humanity.

OR,

"Oh," says the abomination, inhumanly green eyes wide and scared. It paws weakly at the deep wound of its side when Castiel pulls the blade free, stumbling back a handful of steps, gaze unseeing, trembling, before repeating, "Oh."

Then it just... dies.

The light quietly leaves its eyes, the multitude of wings just visible to Castiel's eyes burning away. It feels like it takes a lifetime for it to fall, the white feathery down-like skin flaking away to ash. A body is left behind of a... human child with black hair and foggy blue eyes. He watches it for a moment longer, confused, but nothing more happens.

With a considering look at the golden blood dripping from his blade, Castiel observes as it slowly separate between red and green, sizzling as it dissipates. The blade is clean after a few moments, and he is again just left with silence.

He's just about to leave, blade stowed away, wings arching, when the body moves. Or, rather something wavers, green suddenly bubbling up from the corpse. Castiel redraws his blade, bracing, as the neon bright liquid withers and writhes, folding over and up into the air. It seems to pause, to consider, before ballooning outward sharply and then snapping back.

The thing that suddenly floats before him looks like the dead vessel, or nephilim, creature, but also like neither in a way. The similarities are there in the shape of its white hair, the three eyes, the singular wing and freckles, but not the green skin and half cape, the warrior faulds and tassets, the halo falling to pieces above its head. Castiel stiffens as it blinks, eyes bleary and unsynchronized, gaze looping around.

It lingers on the body just below it, and says in the same quiet voice, "Oh," before noticing Castiel is even there. It's gaze hardens, blazes, and with one smooth motion, draws the angel blade from it's side, wing flaring. "Did you do this?"

"...What are you?" he asks instead.

"Did. You. Do. This?" it repeats instead, drifting closer, and a vague unease fills Castiel. Something isn't right. "This... This is my haunt, how dare you hurt what is mine, scoundrel!"

The angel blade works. It kills the Grace and the human soul. All that's left is the regret and ectoplasm, that desire to protect. A newly born, powerful ghost. >:) Castiel can regret it later.