Unfortunately for humanity, any intelligent life resident on Gliese 581c is liable to have superhuman strength as the planet's surface gravity seems likely to be several times as strong as that of Earth. Alternatively the aliens might be some kind of underwater kraken-men making use of buoyancy to resist their homeworld's fierce gravitation, or perhaps a race of gelatinous slime-oid blobominations.
First time i heard something can use it's personality to resist the gravity that word means (bold one ) of optimistic and cheerful disposition Lol
get ready your vaporizing guns, i mean why not use their own strength against them .