mouthymerc,
As far as I know, there's no RAW cap to how many Signature Abilities a PC could have beyond their career and how many specs they've purchased. It's just that it's a substantial investment of XP to get both Signature Abilities for your career seeing as how you can only attach one SigAbl to a spec, and any further SigAbl need to be attached to a different spec.
Yeah I know. The cap right now is two being that there is only two for each career by virtue of there being just two for each. My concern is that any "universal" signature ability would be, by virtue of being "universal", a go to or must have ability for any lightsaber jockey. That's why I was thinking that something like a "universal" Jar'Kai signature ability might need some pre-reqs. Just a thought.
I'm really not seeing a need for a talent tree or a signature ability, but that's me.
I actually really like the idea of a few Universal Signature Abilities. It makes sense that a few abilities could be developed to useful across multiple careers. I could see a Jar'Kai Master being a universal sig ability, and Donovan's suggestions are bad.
I also think Vaapad is an excellent candidate for a Sig Ability. It would have the unique requirement that it can only be attached to the Juyo spec tree. Windu said Vaapad was more a mindset then a Form, and Vaapad was actually just a "more complete" version of Juyo. So a Vaapad sig ability that allows it's user to channel their inner darkness for boosted Juyo affects would be pretty interesting. It would also be an accurate representation of Vaapad.
Back to the Jar'Kai issue. Jar'Kai's strengths were that it allowed defense against multiple opponents, and that it allowed it's user to "rapid-fire" attack single opponents to overwhelm their defenses. As I've mentioned, there is zero evidence to support Jar'Kai was particularly effective at attacking multiple opponents. So I'm hesitant about giving Rising Whirlwind a blast effect. While I honestly think this version is more balanced and fair, it doesn't actually fit the Jar'Kai's canon theme. You are however fully within your right as a GM to alter the theme if it makes your games more enjoyable!
I did try to make it balanced. I was using the term Jar'Kai as a catch all for all types of dual wielding lightsabers. Some characters might use the blast and others won't or leave it to the GM to make it fit with what he wants.