Unwillingly

Forgetting 

This is late, but for Valindra, it is voidal horrors, most notably when invading her mind, and tears in turn. Knowing the power of the void, and that of the creatures that it spawns, Valindra has fallen victim to their wrath of several occasions. During Arcas, she was tortured by horrors after infiltrating the ranks of the cultists during the tear crisis. On Almaris, both of her closest friends were force-PKed in the hollow. Considering deific magics cannot reach the hollow, she can't even assume where their souls have ended up, if they still exist at all. It all plays into an additional fear of hers, which is her own mortality (ironic for an elf, I know).

I forgot to reply to this earlier on, but my one persona Aiyeis is terrified of watching someone age. She made the mistake of befriending a human in her youth and watched them grow old and weak.