Well because in my universe...



Immortality always has a huge drawback for some of my characters or factions.



You see there is this omniversal sized faction called the Warped Fragments and they worship a chaotic benevolent nigh-omnipotent being and if they in return became a fragment, or in some people's words known as 'Reality-warping unfair battle-happy zealots that charged straight at you like a swarm of angry ants while using the darkest part of outer space as their dwellings.'



They could have engulfed millions of galaxies, but they were pushed back by other half-gods who opposed their chaotic Half-god's spreading influence.



Currently at war with three other omniversal superpower factions that has ridiculous technological levels and all are able to counter unknown source of energies through trial and errors.



Also, the Omniversal Time And Space Continuum Agency (O.T.A.S.C.A) are basically time lords plus S.H.I.E.L.D plus Men in Black police force patrolling everywhere and anywhere, so they are trying their best to stop them from spreading too far.



I mean one of my character who gained immortality through hellish events managed to use if for good reasons and eventually accepted death by being disintegrated out of existence by another violent Half-God before he managed to kill it before he died.



Yeah, basically my universe is almost like Warhammer 40k, but with a little bit of balance and random battles are just everywhere.