What would the effect be, if a lab-coat was used to create a haloween costume.

Dr. Erica Simmons (Gundam Seed), Dr Emit Brown (Back to the Future), Emile Lang (Macross/Robotech) and other such characters are unleased against the dark forces.

Can be used as a add-on to the "Ship of the Line" challenge and "Hawian Shirt Effect", if you want the chaos to multiply.

We all now know of the "Ship of the Line" challenge, so I'll ad a diffeculty too it.
This goes for other challenges as well, the chaos they can unlease.

For: Ship of the Line.
Pic a character for Xander to dress as, that lets him wear his normal shirts, like Howard from Gundam Wing.

Fate/Stay Night crossed with BTVS.

1: Xander dressing up as Emiya Shirou.
2: It can be a canon Fate timeline, all timelines mixed togeter or even crossover timelines because he added some stuff to the costume.
3: The costume becomes a costume at the end of Halloween.
4: Magic of the Fate universe is compatible with the BTVS universe.
5: Xander finds out he has magical circuits (active thanks to Halloween).
6: Xander now has a Reality Marble imprinted on him, with a focus on swords.
7: Xander starts to be a bit more active, resolting in huge property damage, wi...

Atleast three people dress for Haloween as engineers from Star Trek, Robotech and I-War.
Their main space-ship knowhow is centered on the Star-Trek Defiant, the Robotech Garfish and the I-war Dreadnought.
Who they are is up to you, as is the fact on how much they know about certain systems like the transporter from Trek.

They find out about each other while checking if certain places have the materials each would need to prove if their new-found tech knowledge is the real deal.
This checking could be by creating a phaser rifle, a Cyclone or so.
Then they start designi...

Mass Effect, for some reason Ethan has a costume from one of the three games in his shop.
Complete with extra's.

A (techno)witch/wizard takes this costume for some Haloween event.
Race up to you, class as well as long as tech is a part of this class.
Any Eezo brought into being by the spell will disappear after the spell is broken, same for your race.
Though if dressed as a Asari, perhaps a little problem of being pregnant?

No Eezo on Earth, no Relay in the solar system.
If somebody else has dressed as someone from a Sci-fi as Star-Trek, nothing more advan...

Halloween is coming, Xander decides to pull one of Jesse's Halloween plans to the front.
But how to get Willow and Cordelia to cooperate, were to find somebody to take Jesse's place?

The plane:
Xander = Tony Stark (Iron Man I & II)
Jesse = Bruce Wayne (Badman Begins, etc)
Willow = Dominique "Demona" Destine (Gargoyles)
Cordelia = Sylia Stingray (Bubblegum Crisis)

Jesse ain't alive anymore, so if no other person is found to dress up as Mr Wayne, that one is out.
Will Willow go like this or have a lack of faith and go as ghost again?
Does Buffy ...

Harmony dresses as Setsuna Stark, daughter of Toni Stark and Silia Stingray, who also happens to be a student of Doctor Lang.
Atleast, thats her explanation for her Halloween costume, that she made from three costumes she got from Ethan's.
The way she put it together, it uses a hardsuit from Bubblegum Crisis as the main body armor, hands are from the Iron Man suit as well as the power plant window, which she has placed were a medal would hang if worn around the neck on a chain, aka just above the breast armor section.
This lead to a slight raise in the armor there.
For mobility...

Let some female non scooby members have some stuff left from Halloween.
Like the Major (Ghost in the Shell), Seven (Star Trek), Silia (Bubbelgum Crisis) and Rommie (Andromeda).
Shake and stear good, watch the chaos in what-ever universe you set the Buffy-verse in.

Must:
1: Tech blent of the different tech they all know about.
(Their first base might look like it has four sectors with completely different tech in it.)
2: They have to try to get into space.
3: They have to find trouble while exploring space. (Hostile Aliens, for one)
4: Trying to stay unnotic...