When the grand-level powerhouses from the Magic Fantasy World heard Alister mention about having Lilyana Rue Fae as their backer, they were deep in thought about whether to accept Alister's offer.
They wanted to become gods. Reaching demigod-level or grand-level didn't grant them eternal youth and everlasting lifespan so some of them were nearing their end.
The only way to increase their lifespan was to ascend to a higher power level but Alister's gate-keeping had hindered them from becoming a god.
Of course, they could still become a god regardless if they accepted Alister's offer. But with how ruthless Alister was, he wouldn't hesitate to kill them if they posed a threat to him by becoming a god yet not submitting to him.
Only those from the dragon race and spirit race had near-infinite lifespans since even those elves only had higher lifespans than most humanoid sentient races but weren't that high.