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Wait, interceptor sounds like it would be fast, and more suitable to Aya. Is there anything with a lot of homing missiles?

I assume that's huge...

Because under normal circumstances it's not controllable, nor does it exist wtihout a carrier.
That would be solved if I made it so that there was one interceptor in a carrier, named the carrier Hakurei Shrine and came up with an excuse as to why exactly her shrine is strangely mobile. Which could be a marginally original storyline.
OR we could just make Reimu into a carrier and consider all the interceptors her danmaku. However, then she'd be sloooower. D:
EXCEPT, A CARRIER FITS ALICE MUCH MOAR.

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So the tentative and unfinished list right now will be:
Reimu: Ehhh, I had an idea until I made up my mind about Alice. xD

Marisa: ...Wraith.
You know, I think that the Battlecruiser will not be Marisa. The battlecruiser will be an auxillary shoot and to do Master Spark, I figure. Because otherwise she'd be too big and slooooow. A wraith however I think fairly represents Marisa's speed on a broom it shoots lasers. : D

Sakuya: Medic<3
Le Mahouya would have no inital combat abilities, but should be able to pull out knives (hydralisks) and "stop time" by disabling units in the vicinity.

I'm thinking of having another character to pair up with Sakuya (Like Reimu with Marisa), but I don't know what's reasonable to have. It's not like Remilia would go out if she didn't have to, Flandre could but I don't feel like making an excuse for her to leave, Patchy's basically a Hikikkomori and couldn't take the traveling, and China needs to guard the gates...So....Koakuma?! Nah.
I'll think about it later.

Thus far, the non-playable characters:

Arisu: Tassadar (Carrier ver), or the normal one, doesn't matter.
Well it's obvious. The interceptors are her dolls~
Because of that, I think she can be done fairly traditionally without any fancy trigger abilities.

Youmu: Fenix (Zealot)
I'm pretty sure this should go uncontested. Fast melee character. Her Myon would be a science vessel that can use defensive matrix and emp (to neutralize shields and energy (that means no Yamato and not shields for the carrier) that would spawn scourges when near air enemies, her only anti-air attack which makes her offensively weak against Reimu and Marisa. She can pose a big threat to Sakuya by having an ability that teleports her next to the maid and spawn a dark templar for a single hit. Consider it a runpast.

...
Why do I see Sakuya chucking Hydralisks at people?

And now the thought mutated to Sakuya throwing Ultralisks around. ._.

if you truly want my suggestion.. look up bounds and the frogger map.. if you still want to make a touhou like game for sc, feel free, lol..

and just fyi guys, intercepters cannot be forced to make movements, they are classed with the carriers and thus will explode if they don't have a carrier to return to.. they only move when they are coming out of the carrier and attacking something.

I assume everyone knows nothing because it makes it that much easier to explain the right way to do things =p
particle arena has carriers.
you see, what you need to do is to bend the rules, not break them.
that or wait until sc2 editor comes out so the rules aren't as rigid =p

you asked for suggestions, therefor, i gave one.
I do hope you're actually making it a scroller map instead of a stupid rpg map =)