>>45942606>Arceus Thought to have created the universe, thus presumably able to exist outside the universe - probably the closest thing to fully immortal that we've got
>DialgaThe embodiment of time, therefore would last until the end of time
>PalkiaThe embodiment of space, therefore would last until the end of the universe
>EternatusInfinite source of energy, able to alter space-time so most likely immortal (unless something is strong enough to kill it)
>DeoxysInfinitely adaptable, regenerates itself and can survive in space, probably near-immortal
All others are probably exceptionally long-lived, but not truly immortal. Some like Rayquaza, Groudon and Kyogre are virtually unkillable but probably wouldn't be able to withstand the destruction of the Earth.
