#some sort?

They don’t seem to be threatening.. are they? Their just standing there. Watching us in the rain

It’s a dragon and its rider for sure but they seem.. odd. The dragon looks to be some relation with a light fury, but with what? Is it a hybrid? I never seen a fury like that before, have I?

The stranger is to be asked about; his hair white as snow, same could be said about his skin, a staff with a hook for an end, piercing icy eyes.. Was he a shepherd of sorts?

(This being a personal take doesn't mean I believe this wholly to be true or it being a theory with evidences supporting it. This is made for fun. You can post your own takes as well!)

(BONUS: My own take on the battle scenario. Gaster is depicted as Redacted here because it is his final form, just like Spamton in his NEO form).

Motifs:

Gaster's battle theme would be an arrangement of songs such as Freedom, ANOTHER HIM, Darkness Falls, and Don't Forget.

CORE / Another Medium / Patient could also be included. An arrangement of 'D.ogg' + Flashback and The ID from Earthbound: Halloween Hack could be used as the intro and outro respectively. The Legend + The Dark Truth could appear in certain segments, moreso if said segments are intense.

If Gaster in Deltarune is the same from Undertale, Once Upon a Time could be expected. Mus_smile (i.e. the garbage noise) and Giygas' Static sounds from Earthbound could appear occasionally at the background, emphasizing Gaster as a being beyond our comprension. Also, an arrangement of Penumbra Phantasm would be interesting to hear in different parts of the theme.

General (Title, Length, Genre):

As for the title, options like "AGAINST HIM", something referencing the devil, such as "BATTLE AGAINST THE DEVIL", or maybe a parallel to Don't Forget, something like "REMEMBER ALWAYS", could be suitable. If Gaster as a character is a reimagining of Halloween Hack's Dr. Andonuts, the title could be a nod to Dr. Andonuts' Rage (the original file name for Megalovania), for example, "WRATH OF THE BROKEN DOCTOR."

Alternatively, the title could be related to darkness, shadows, or Gaster's entry number seventeen as a whole.

The duration of the track would be around 6 minutes, as Gaster is related to the number six, making it Toby Fox's longest track in Deltarune (as of now if he will keep making music ranging up to 2-3 minutes in length. On a side-note relating to this, the full version of Penumbra Phantasm could be one minute longer but who knows?).

As for the genre, it could be dubstep, heavy metal, or even experimental, a play to the nature of Gaster's character as the former Royal Scientist.

That should be all from me.

I never though I would need to see Marco with pink lingerie in my life. Also I can’t see Bertholdt in any other color than black? It suits a shy boy. Please don’t mind me >///<