While I feel there's no other character that Fukua's moveset is a perfect fit for, I think Ileum is probably the closest. Ileum seems like the only one that could have moves similar to Fukua's while still feeling vaguely similar to her intended playstyle. Yeah, she'd lose out on having that epic Dhalsim reach, and those crazy transformations, but everything else is fairly on par for her. She could not only mimic the function of Fukua's moves, but the relative appearance of them too.
Obviously Ileum is very flexible to begin with. She could spin her limbs for drill attacks like Fukua's (she even has little drills on her arms anyway), as well as use those limbs to pull off some ferocious grappling. Also, since one of Ileum's gameplay inspirations is Toxic Seahorse, the trajectories on her acid projectiles would probably be very similar to Fukua's Love Darts, especially the LP one. On top of that, consuming and spewing opponents, like in Fukua's Lv3, could already be considered a standard tactic for Ileum.
Anyway, regardless of all that jabber, I'm just reaaally glad Fukua is her own character!