I explain from the Sefer Habris the 25 levels of neshama. Nefesh, Ruach, Neshama, Chayah, Yechidah, starting from nefesh shebenefesh, ruach shebenefesh, etc. As a person elevates himself, the yetzer hara becomes stronger, כל הגדול מחבירו יצרו גדול ממנו, so he gains a higher level of neshama in order to balance each other and be able to fight it on an even level.
