Valt:   Achluophobia- Fear of darkness.

Silas:   Isolophobia- Fear of solitude, being alone.

Free:   Necrophobia- Fear of death or dead things.

Cuza:  Arachnophobia- Fear of spiders.

Chris: Fear of losing friends (I don't think this specific one has a name, but she can't bare the thought of losing Free, Whether it's him dying and not wanting to be her friend anymore.)

Lui:   Asthenophobia- Fear of fainting or weakness.

Aiger:  Athazagoraphobia- Fear of being forgotten or ignored

Suoh:  Gelotophobia- Fear of being laughed at.

(This took me WAY too long to research, So i'll stop here. Do you want more bladers phobias?)