So before, she was just an angel.
But now she phases through Angel, Archangel into Seraph.
What was the mythological stand point for Kayle to become a Seraph instead of just an Archangel? By now she's almost upon the status of god.
Kayles gameplay is all about being weak early game and becoming more and more powerful throughout the game, so her gaining more wings and thus basically going through the different ranks of angels.
In the lore Kayle isn't really an angel, she is a human who was infused with divine powers before her birth (same goes for Morgana), she simply looks like an angel(angels don't really exist in the league universe). However Kayle rejects her human side and strives to be the perfect divine being, so her rising up through the ranks of the biblical angels symbolizes her getting closer to that ideal.
Now this is a fun question.
The word seraph (plural seraphim) is used in four locations in the Bible. The most well known is in Isiah 6, where the word is simply transliterated into English and refers to celestial beings of some kind. Aside from describing them as having hands, feet, a face, and six wings very little information is given on them.
Things get more interesting when you look at the other three references, which describe venomous snakes sent in judgement (in Numbers) and flying/winged snakes (a poetic description of a cobra's hood, probably) two other locations in the book of Isaiah. The connection to serpents is interesting, but things get more interesting when we examine extra-Biblical writings, the book of Enoch in particular. It's written in Greek and describes seraphim as δράκων, or dragons (serpents).
There's a pretty strong case that seraphim were intended to be celestial dragons originally, but that description has changed over the years. Especially among Christian iconography due to the association between dragons and the devil (as per Revelation).
So is Kayle a seraph? If we're going by the modern interpretation, yes. Six winged celestial being associated with fire. If we're going by the (likely) original intent? No, she is not a snek.
Don't forget morgana also has 6 wings, and is also a seraph. Unlike Kayle, Morgana keeps her 6 wings throughout the whole game and thus is a seraph the whole game. however (as visually shone), she has just chained down her main wings so they hang limply behind her. They do become unchained in her ulti though
Archangel > Seraph
She's an angel not a font...
:/
