coming from the one who couldn't remember who Yu Yevon was, I'm not surprised you don't remember him attacking.
Seeing as pretty much NOTHING in FFX fires bullets, your point is invalid. ha ha, old chap.

Seriously, though. His lack of numerous attacks isn't the problem. the problem is that you fail to see that at least Yu Yevon has attacks that can be transferred into Danmaku ones. unlike Tidus, Auron, and Wakka sort of. The point is that your going to have to make most of them up.
and FFX had no oversoul system. that was FFX-2. perhaps the international version that added the new game+ had one...
and the song you're thinking of is the Yu Yevon's first theme. When you have to beat your underpowered aeons with your overpowered weapons in a couple hits tops. Personally, I like
Yu Yevon's second theme better, but that's likely just a preference thing.
Evil religion overused? the only other game I can think of like FFX that uses that is real life.

Seriously though, no one really cares about the religion, It's just the whole idea of Yu Yevon's character that I like. A character whose only desire is to summon... and apparently to destroy things, since he knows Ultima.
Also: I don't want to come across as a whiner whining about "I want Yu Yevon, WAAAH!" because that's not what I'm doing. Sure, I want him, but I'm saying- OOH!
IDEA: you said there were three playable Touhou characters, right? What if Yu Yevon's first couple Gauges were the characters you aren't playing as, and the last two gauges would be a normal attack with Yu Yevon's true form, and a short spellcard with his Ultima attack, and the last one would probably be this over the top thing based on the kick-ass way he died. (It would still be a spellcard, just based off his death)
...sorry about that, I got that idea right as I was typing.