The targon champs are channeling. Aspects of great. Power. Illoia is a bearer of a gods will/power, and I tho k janna has been retconed into a winf spirit from the cliff face that piltover and zaun are built into.
Are there religions in runeterra though? Does Demacia and Noxus have national religions? Organized church orders? Lucian could easily be a member of exorcist like clergy from a demcian church task with destroying undead
There are some in Zaun-Piltover who revere the "Grey Lady" (and that's NOT Camille). There are also a bunch of traditions, like leaving all the windows open on Progress Day. 
is seen as a guardian angel to Zaunites.
believes in entities he calls the "World-Makers". Given his age, this may be an otherwise extinct religion.
and her tribe follow the "Great Weaver". Other tribes likely have their own faiths.
Ancient Shurimans worshipped the sun, which may indicate a link between Shurima and Targon. There is still sun-worship in modern Shurima, but it may not be the most prominent religion anymore.
Noxus has an order known as the "Tallymen of Kindred", though wether they view Kindred as the Lamb and Wolf or some other form is unknown. 
was part of this order once.
For that matter, 
is known to all Runeterran cultures in one way or another.
used to be a figure appearing in religions all across Runeterra, but this may no longer be canon.
Demacia's cultural psychopomp is the "Velied Lady", referenced by Lucian in Shadow and Fortune.
is a cultural symbol of Bilgewater, in addition to Nagakabouros, although he isn't so much worshipped as acknowledged.
The Solari faith is dominant in Targon, and the Lunari have been wiped out.
EDIT
I forgot the best one: Shurima has cult devoted to 
! Every year, his devotees somersault through the cities as an act of faith, and lead marches into the desert in the hope of meeting their god.
There is the augmented cult in Piltover/Zaun.
Not too sure, but I believe the blood moon cult would be considered one (however its a non-canon skin line)
However there is only one true religion in runeterra: 
There is the Thieves guild
in Noxus which believes in Nocturnal
