Probably the Zentraedi are going crazy in buying any means to expand and shrink from the black market: the Szalinsky (sp?) shrink ray, Pym Particles, those cakes and beverages from Neverland… Titan Shifter DNA is useful for them because not only is it "shrink/grow" stuff, but essentially gives them access to biological powered armour. Guyver without… well, a lot of cool stuff a Guyver has, actually. And still impressively nasty.
Don't have "Unearthed Arcana", unfortunately, but the idea of essentially making the Titan Shifter an Advanced/Prestige Class route with options to give the Titan shape as you go through it actually sounds kind of cool.
Although guess this part of the game is easier in Mutants and Masterminds terms, yeah.
Nanoha… well, I was thinking of a detail for it that is probably too dark. Also needs work on a detail haven't worked on in RP terms.
One of the things mentioned on some of the stories for Coreline posted on DevArt is a mutation called a "Pariah Gene"-essentially a pretty powerful power nullifier. Psionics, superhero powers, magic, blocked and blocked HARD. Guy with a Pariah Gene against a Nanoha-verse wizard is like the Huckebein (or as people probably nick-name them in the setting, the "Hucks"-like "Zeds" for "Zombie") only without the biological need to kill and more ease to put down by conventional means (unless the guy with the Gene is packing something like powered armour and the wizard doesn't even has a pen knife, and then the wizard is SCREWED). The Gene only nullifies the power-the carrier needs to do the rest of the job. Obviously with the crazy that the setting is, a lot of carriers have been forced to become bad***es.
Or seen from a different angle, it's the Pariahs from 40K only more (super-) heroic.
Of course, there are those at TSAB that don't like this Gene, and there are those within that group that are all for rounding Pariah Gene carriers and putting them in front of a firing squad just for existing.
So TSAB has a bit of a secret war going in its corridors while the agency tries to continue its job of policing time and space best it can (guess it has forged alliances with Gallifrey and such).
Dig the ideas for Nanoha, BTW. May try to get art of them… think Nanoha as X-23 is too crazy?
I could actually see some Zentraedi factions being VERY interested in the whole Shifter business.
The ability to shift between Zentran and Micron sizes without the need for all those machines?
And faster too, to boot.
As for the "biological mecha" comment, I could actually see an alternate of Asuka Langly, either with or without her EVA, fighting Titans as part of her "training" time in Europe.
One potentially big "Oh F***" moment would be something like the Zerg harvesting the shifting DNA.
"Attack of the 50 Foot Kerrigan" would be the least of our worries....
Those characters as player options, oh that's going to be a bit trickier.
Mutants and Masterminds ruleset will likely have it easier compared to D&D/Modern ruleset, thanks to the point buy and such.
Heck, in effect Titan Shifters aren't that much different from Hank Pim/Ant Man's "Giant" mode?
As for D&D/Modern, I'd think the "Bloodlines" section of Unearthed Arcana could be beneficial as a starting point.
As a mayor bloodline, you'd be taking up to 3 levels in the "titan shifter" bloodline (which are a slightly less harsh version of +1 LA each) and you'd get a set of bonuses/abilities as your total HD reached certain levels.
the 2 other bloodline types take only 1 or 2 of those levels, but also gain less benefits and also slower vs the mayor line.
As for the "take a hell of punishment", well just the size upgrade alone would add a decent chunk of constitution score (and thus HP) in D&D/Modern
Of course, we must remember coreline is a setting where if the Titan is unlucky, they'd run into an 8 year old with a personal ion cannon or something.
Granted, most version of Nanoha might not kill it.
A version of Nanoha allied with / recruited into the Weapon X program however....
Speaking of Nanoha alternates, I could certainly see one of those wearing the mark of certain Magic Guild in the city of Magnolia from the kingdom of Fioré.
