Kindred is the first champion to not have their icon derived from their artwork (considering theirs is a two-for-one case) as well as the first whose release was celebrated with summoner icons (one for Lamb and one for Wolf).
Kindred are Runeterra's spirits that embody death.
Lamb ends those who have accepted their fate.
Wolf chases those in denial of their end.
Morality and actions in life do not matter, only the way one chooses to die.
Kindred are a mythical being, known only in legends and folktales. They have many names (Ina and Ani, Farya and Wolyo, others, but they are always Lamb and Wolf, the Kindred) and their masks are a universal symbol of theirs, yet their existence 'per se' is only known to the dead or those few who almost were.
The Noxian tally-men illustrate a case of pseudo-worship.
In 'A Good Death' the actress Magga encountered the Eternal Hunters in Demacia (pre-Jarvan III) while it was not yet her time. This depiction is the in-game one (just like how gamblers see Tahm Kench and how he himself is seen in-game)
Their large presence grants Kindred many insights.
The Shadow Isles are not welcome to them and in their eyes its undead are a mockery of the cycle of life and death they uphold.
One of the many legends surrounding the origins of the Kindred tell of 'a pale man with dark hair' (Runeterra's own Grim Reaper) who was 'very lonely' and so split himself 'right down the middle' so he 'would always have a friend'.
Assuming there is some fact to this tale, one can extrapolate that his emotions (materialized in his dark hair) became Wolf, while his rationale (materialized in his pale self) became Lamb.
This would 'explain' why the Kindred are two halves of a whole and why one has what the other lacks (Lamb's cold reason, Wolf's hot instinct)