Long story short, Nocturne is the demonic incarnation of wrath in the spirit realm created by a bunch of desperate and (frankly) idiotic warrior-mages during the Rune Wars. Sound familiar? It should.
* Evelynn was truly 'born' during the Rune Wars after eons of comatose, created by the pain & agony of those involved.
* Evelynn, per her own lore is described as "a demon, a ravenous **spiritual** parasite that **fed on the basest of human emotions.**"
* Evelynn is heavily in tune with the realm of shadows.
My question is this: Can we assume Evelynn is also a demonic incarnation of sin (in this case, lust) that is **capable of moving between the spirit realm and the physical realm?** And if she can move through the spirit realm of her own volition, **how does this impact her relationship with Nocturne**, whom of which CANNOT escape the spirit realm completely.
(Scathlocke I don't wanna hear you come out and say 'Nocturne doesn't know about her' because both demons have been active, both are extremely similar and if the spirit realm theory holds up then Nocturne should've almost definitely noticed her presence after being so occupied freeing it of others before.)
As a side note, just as conjecture:
Wrath or Envy: Nocturne
Gluttony: Tahm Kench
Pride: Mordekaiser (yes, Morde - I have a feeling this'll become even more apparent in his VGU)
Greed: Elise (constantly wishing to preserve her own beauty and take it from others)