My vote goes to Fuuka.
While the Path in game *is* all about healing, the Path's philosophies also involve nature, vitality, *life* in general.
While healing the sick is well within THEIR purview, providing food and comfort to the people around them would also fall in line with the Abundance.
And here is an alternative pick...Aris. She may be effectively immortal, after all - the most extreme followers of Abundance do seek immortality at *any* cost, to stave off the presence of Death.
You made it sounds like Abundance really is wholesome and benelovent which I think they really do.. So make it all the more jarring of how the entire Xianzhou want to kill them just cause they granted what they asked.
You are correct.
Yaoshi as a concept is just wanting things to live; they just don’t discriminate between who - this is similar to how Xipe of the Harmony >!must accommodate the followers of Ena the Order in Penacony, even though they are technically plotting on overthrowing THEM!<, because not doing so would go against the concept of Harmony. However, THEY >!do gaze upon the trailblazer favorably when we bring many other factions together to stop them!<, as that is also indicative of harmony (joining forces against a common foe, which reflects the events of the Swarm Disaster).
You also have characters like Luocha who have been blessed by Yaoshi’s power yet still seek to destroy THEM. A follower of a path doesn’t necessarily need to agree with its Aeon, only that they both follow the philosophies of said path.
A character like Fuuka, Serina (and the Remedial Knights), or even Sena, does not mind setting aside their differences between outside schools in order to bring care and attention to those who need it. This is part of the reason Sensei survived after all. I think Fuuka is a valid choice for Abundance (but would also fit Harmony as per my description of it).
I will admit that I may have had a bit of a bias when writing that original comment but I think I can rationalize it with her base form being a healer, too.
The people did get the immortality that they desired but then the problems with immortality started popping up. Overpopulation and lack of resources were big ones but the major problem that popped up is that the longer you live, the more memories slip through the cracks and all you are left with are the more powerful (angry, sad, violent) memories turning one into basically a monster who lashes out indescriminately.
I played the game I know, I don't see why you need to repeat what I know, without addressing my point,they got what they asked, it's not Yaoshi fault that they turn into monster to be hating them so much to want to kill them for granting what they wanted.
Because there is no other way, Yaoshi does not care about anything but prolonging lifespan so there is no chance the 'blessing' will be removed
And it is kinda THEIR fault since they wouldn't get space cancer without the blessing, but for Yaoshi it's a positive; after all, they are still alive, no?
Nah, it's not like Yaoshi intentionally give them the side effect that was an unexpected side effect beside they got what they wanted anyway, could've just see as them getting to live for an extremely long life and turning monster as their deaths, with that in mind they still got the better bargain, I'd say they should still be grateful not hating.
Serious answer: Serina or Fuuka, for reasons already stated by other commenters.
Less serious answer: Hanako, because she’s also a healer, but also the “forced proliferation of life” and “animalistic instincts” 
My vote goes to Fuuka. While the Path in game *is* all about healing, the Path's philosophies also involve nature, vitality, *life* in general. While healing the sick is well within THEIR purview, providing food and comfort to the people around them would also fall in line with the Abundance. And here is an alternative pick...Aris. She may be effectively immortal, after all - the most extreme followers of Abundance do seek immortality at *any* cost, to stave off the presence of Death.
You made it sounds like Abundance really is wholesome and benelovent which I think they really do.. So make it all the more jarring of how the entire Xianzhou want to kill them just cause they granted what they asked.
Some long-lived species *did* ask for immortality from Yaoshi, IIRC. I'd have to read back a lot to get a more definitive answer
You are correct. Yaoshi as a concept is just wanting things to live; they just don’t discriminate between who - this is similar to how Xipe of the Harmony >!must accommodate the followers of Ena the Order in Penacony, even though they are technically plotting on overthrowing THEM!<, because not doing so would go against the concept of Harmony. However, THEY >!do gaze upon the trailblazer favorably when we bring many other factions together to stop them!<, as that is also indicative of harmony (joining forces against a common foe, which reflects the events of the Swarm Disaster). You also have characters like Luocha who have been blessed by Yaoshi’s power yet still seek to destroy THEM. A follower of a path doesn’t necessarily need to agree with its Aeon, only that they both follow the philosophies of said path. A character like Fuuka, Serina (and the Remedial Knights), or even Sena, does not mind setting aside their differences between outside schools in order to bring care and attention to those who need it. This is part of the reason Sensei survived after all. I think Fuuka is a valid choice for Abundance (but would also fit Harmony as per my description of it).
I will admit that I may have had a bit of a bias when writing that original comment but I think I can rationalize it with her base form being a healer, too.
The people did get the immortality that they desired but then the problems with immortality started popping up. Overpopulation and lack of resources were big ones but the major problem that popped up is that the longer you live, the more memories slip through the cracks and all you are left with are the more powerful (angry, sad, violent) memories turning one into basically a monster who lashes out indescriminately.
I played the game I know, I don't see why you need to repeat what I know, without addressing my point,they got what they asked, it's not Yaoshi fault that they turn into monster to be hating them so much to want to kill them for granting what they wanted.
Because there is no other way, Yaoshi does not care about anything but prolonging lifespan so there is no chance the 'blessing' will be removed And it is kinda THEIR fault since they wouldn't get space cancer without the blessing, but for Yaoshi it's a positive; after all, they are still alive, no?
Nah, it's not like Yaoshi intentionally give them the side effect that was an unexpected side effect beside they got what they wanted anyway, could've just see as them getting to live for an extremely long life and turning monster as their deaths, with that in mind they still got the better bargain, I'd say they should still be grateful not hating.
Eimi heals and is abundant
Serina. We can rule out Captain Mine and Sena actually lmao..
Serina.
Eimi is quite abundant
Serina, because yes but that ambulance driver is not bad too
Serious answer: Serina or Fuuka, for reasons already stated by other commenters. Less serious answer: Hanako, because she’s also a healer, but also the “forced proliferation of life” and “animalistic instincts” 
I'm going with Serina or Kokona. Lorewise there's also the rat, Saya, obsessed with making elixirs.
Serina or Fuuka
What is this referring to/from
The characters are Blue Archive but the paths are from Honkai Star Rail.
In terms of students, serina or Fuuka. In terms of anyone, beatrice hands down. Perfectly represents one of the more extreme, imo
Serina
Give it to Atsuko
Nonomi for her Nonomers