Riot, since you're changing the lore, let's look at Taliyah (and Azir and Sivir).
The idea that Yasuo was Taliyah's mentor isn't bad. The idea that Taliyah is now on a quest, a journey of discovery and growth, is great.
But here's the thing: Taliyah's rock-based powers are unexplained. They're just..... there.
Now let's look at Taliyah:
- has an evident bird theme
- controls rocks
- is from Shurima
Then let's look at Azir:
- has an evident bird theme
- controls sand (broken rocks)
- is from Shurima
It seems so logical to conclude that the explanation for Taliyah's unexplained stoneweaver powers is that she is actually a descendant of Azir. It also fits perfectly with how they both share the bird theme. And imagine the antagonism that could develop between Taliyah and her ancestor Azir.
Let's look at Sivir, now. No bird theme, no stone/sand powers, no particular relationship of antagonism or friendship towards Azir.
Since we're altering all the lore now, to the point of making big changes (see Warwick for example).... I think it's time to make Taliyah the descendant of Azir, therefore catching............. two birds with one stone.
As for Sivir, focus with her antagonism with Cassiopeia instead.
Sivir is already a badass, she's pretty much Xena. Taliyah is an everyday girl.... with the heritage of an ascended emperor.