Honestly, this Immortal Function is still a mystery to me, it seems that different people have different abilities, for example, the blind man who is an acquaintance of MC's teacher, who can 'stop time'. And for MC himself, it is still unclear what his IF ability is, what he does I think is just the tip of the power of that ability itself, not yet fully.
Is it beautiful because it ends or does it end because it is beautiful?