User blog comment:KaiserLos24/New Shadow Isles Champion- Kalista (Maybe :P)/@comment-25606700-20141031215036

All 7 of those champions betrayed their humanity in some way.

Cassiopeia stabbed Sivir and became cursed in the form of a Lamia.

Hecarim is alluded to have been human at one point (West TT Altar), and betrayed his humanity to gain power and eventually become twisted to the will of the Shadow Isles.

LeBlanc has been around for ages (centuries) pulling the strings of Noxian Aristocracy from the shadows meaning she must've done something to at least revoke her mortality.

Zed threw away his humanity when he embraced the shadows and was twisted by them; he also killed his "father".

Twisted Fate threw away his humanity in an experiment in Zaun to get closer to his dream.

Lissandra threw away her humanity for immortality and power.

Xerath threw away his humanity in the ascension ritual by betraying Azir to gain "limitless" power.