are you familiar at all with Particle Forge (PF)?
Do you have Rebellion or Trinity?

Few ways to do it. I would make a texture.anim file which would have maybe 6-8 spheres on the texture.tga with each sparks a little different. Create the texture.anim file to call each postion of the frame and use that texture.anim in a particle effect.

Use notepad++ to do a find in files for .texanim in the reference file Particle folder.

Buff_VengeanceSmall.particle uses fireyflair.texanim

C:\Program Files (x86)\Stardock Games\Sins of a Solar Empire - Trinity\TextureAnimations

TXT
textureFileName "fireyflair.tga"
numFrames 14
numFramesPerRow 14
startTopLeft [0, 0]
frameSize [34, 128]
frameStride [36, 0]

So, I would start by making a copy of that particle and renaming it, load it up in PF. Make a new .tga with the frame spacing and a new texanim that calls the .tga and the particle that calls the texanim.

start you there.

The damn Romulans stole your technology! 

xsi.soase.x90x.net/Particles/Tempest_Particle/ScreenShots/TempestScreenShot.jpg

xsi.soase.x90x.net/Particles/Tempest_Particle/ScreenShots/TempestScreenShot2.jpg

Ya, I oversize them when I get in game, size to fit after textures are done

Textures smoke4.tga and plasma2.dds are stock textures. I would rename them and edit to suit, then connect new texture name to the particle.

TextureAnimations\tempest.texanim

TXT
textureFileName "tempest.tga"
numFrames 12
numFramesPerRow 6
startTopLeft [0, 0]
frameSize [90, 90]
frameStride [92, 92]

tempest.tga started as the spacing, 2 pixel spacing between each (frameStride).

Added some screenshot cutouts, rotated a few, removed black backdrop spacing. You may want to add more frames, or add the orb using a different texture set to rotate, I would at least animate the sparks and add the light blue clouds as a point effect and the orb as a point effect.

loaded the anim in the particles 1st point
added a glow effect to the ball
added the dark blue plasma effect
added a lighter blue smoke trail effect, you need to change this texture to match your effect but the trails are attached, you just need to mess with the numbers and colours. Same with plasma effect.

All the files you need to load what I did are here..
xsi.soase.x90x.net/Particles/Tempest_Particle/

to attach the effect, just find an existing ship entity with a missile weapon type and change the travel effect name

missileTravelEffectName "Weapon_PhaseCapitalMissileHeavy_Travel"

to

missileTravelEffectName "TempestLarge_Travel"
 

Should get you well on the way. So many options and routes you can take, only really limited by how much time you want to edit each frame and the other textures.

And it glows just fine. 

I went ahead and looked at the Tempest projectile in sc2, and it's surprisingly ugly/wasteful. It's also not comprised of any animated textures. I don't really like the idea of pulling it out of compressed screenshots, though. Personally, I try to avoid anything with so much obvious artifacting (about half of the particle textures I would have used were unsuitable for similar reasons, but then again, I am strict on quality).

I think grabbing a series of screenshots out of the sc2 editor would much more suitable if you wanted to turn it into an animated texture, particularly since you'll probably be able to grab transparency, actual animation as opposed to just rotations of the same frame, and higher resolution.

The "glows" you get from sins are incomparable to emissive maps. Once you play with a real material system there's just no real going back. You can fake them all you want, but the control of doing it at the texture level is incomparable for a lot of effects. :3

 But, again, that's only if you want to go the extra mile for quality. For me, it's no contest.

Well, let's assume that the OP is in possession of sc2. This is what it actually looks like in sc2.

The reason I bring up the particle limitations in sins is obvious. If we want a faithful recreation, we need to know what we can't do and how that effects us. This particular particle only owes some of its effects to emissive (namely the center and the glow on the exterior), but it also uses several meshes and what appears to be some kind of falloff effect on the ring.

So you can go about this two ways. If you want a faithful recreation, you can build frames out of the sc2 editor with a black background, preferably using something like fraps to cap the full loop and then split some of those frames into a sheet. Alternatively, you can try to recreate the actual system in sins. The latter is possible in this case minus some details, but it won't look as good because alpha and additive blending can't really achieve the same kind of intensity unless you start overlapping stuff and wasting particles. For someone looking into break PF, I'd recommend learning efficiency first and shiny next. God, my old particles were horrible.

The second way you can go is the way you suggested. Even so, I still suggest using a cap out of the editor to get that black background for best results. If you don't care about being faithful, well, whatever then, but the Tempest projectile is fairly unique in its appearance and the "glow" overlap you're going to get out of a screen cut is not really going to give it a faithful appearance.

If you want, I can get you some pngs or tgas to work with.

/edit

I swear every time I refresh this forum, something either breaks or changes. There was an advanced search display in the weirdest of locations one time around, and sometimes the icons break or change.

Here's some pngs I capped from the editor, if you're interested. I think if I really wanted to get deep into rebuilding this, I would remove that white texture that acts as lightrays, and have an independent one inside sins so I can control its brightness a bit better.

http://www.gameproc.com/meskstuff/wibodsbasement/butterandcats.7z

Always TGA, and yes please, that will be a nice particle for the community 

EDIT: ya I lost a post 

Got your pngs, and I agree it should be broken into separate parts.

Depending on how big and slow it is, the more detail it should get ,
fast and small I would just use what I already made. 

thanks 

that would be great 

put what you sent here
xsi.soase.x90x.net/Particles/Tempest_Particle/ScreenShots/ 

http://xsi.soase.x90x.net/Particles/Tempest_Particle/ScreenShots/tempest01.png

Now we're talking. Those are starting to look pretty fly. Unfortunately, as I can see, since it is additive the whole thing tends to blend uniformly. With such a complex texture spawning multiples would not be ideal. This is something I'll keep in mind when I look through the game for additional things.