Reading Morgana's updated short bio, I think it has the potential to go in a really cool direction.

Driven by vindictive obsession, Morgana is a potent mistress of suffering and the black arts. Once a being of grace and light, she was ripped from her kind during an ancient conflict that broke her soul, turning her into the cruel tormentor she is today. Comforted by a prophecy that claims she will strike the final blow and gain her revenge, Morgana lies in wait, her lust for power growing endlessly.

Now I know some people read this and thought 1) this might make her a bit too one-sided villain or 2) she sounds like a victim of the conflict rather than the initiator of it (I agree with the latter by the way, give my first main more agency), but I thought one thing:

Lucifer

https://i.imgur.com/0PkK36T.jpg

This can be absolutely amazing. Judeo-Christian mythology is at least as awesome as the Nordic one, and if Riot puts their art team on that and delivers a gender-swapped Lucifer(in a subtle and tasteful way) I am hyped and sold. Add to that how the worship and fear of this entity influenced the culture of Valoran throughout the ages and it can turn out solid. Give me "Paradise Lost" and Milton's poetry, Riot. Give me mature and well-crafted Runeterran myth. I know Season 6 faced some backlash because the characters were 2deep and sometimes preachy, but you more than compensated in Season 7, which was more mass-market. I hope the seasons to come strike a good balance.