I suspect many look for any excuse for any gift to be potentially corrupting I often suspect this is more indicative of something on them than the rest of us, however there's also a reason horror movies resonate with us so I could be digressing 🤔 Most of the ways I think of having invisibility or immortality typically puts me in the position of a naturalist capturing the rarest glimpses of nature man has ever witnessed. Or in the case of immortality keeping a chronicle of humanity through my existence preserving knowedge and teaching it to future generations when it is time. 🤔
I think the corruption hypothesized in both is to do with avoiding/evading accountability on the one hand and on the other becoming distant/estranged from others.
In the case of invisibility Plato posited that being unseen resulted in being unaccountable, that is to say that the ultimate or final check on wickedness is the sanction and censure of neighbours, family, the public, others of all descriptions.
This idea has been a feature of every story of invisibility from Plato's time right through to HG Wells and all those hollywood movies. To some extent the "I see you" version of sanction/censure has lasted longer than any myth about invisibility, the panopticon, surveillance, early prison reformers all believed that visibility, provided it was constant enough, would reform character and stop crime or deviance from lawful norms.
Immortality, kind of, operates on the same principle, when everyone becomes a "creature of a season" while you live long enough to watch them come and go then, as the Highlander movies and Queen song puts it "Love Must Die", or as the philosophers or psychologists would have "love" the capacity to "relate", any "attachment" or "social instincts and drives".
The immortal is not corrupted as they are unseen or unnoticed and no subject to the sanction or censure of others but simply outlive it and care less about it consequently. They have less of a shared experience with others arising from fearing or expecting death as inevitable.
In the final instance the lack of accountability and estrangement from others will contribute to viewing others as objects, means to ends, not ends in themselves and without intrinsic value (granted this is Kantian ethics rather than practical reason or virtue ethics, ie the only intrinsically happy/satisfying life is the virtuous one).
I do see how either invisibility or immortality should permit individual or social/utilitarian good, the longevitiy allows that chronicling role, you could also accumulate commanding stakes in the economy, finance etc., presumably, its a question as to whether or not this could be a sustainable arrangement or if it would fall prey to the corruption I outlined there. It could be a question of time scales. I'm not sure.