So we have death established in Runeterra... Where is the direction of lore going?

A whole pantheon of mythical characters. All of them kind of existing, but kind of not. All of them having stories and mysteries about them and affecting the world because people believe in them. All just bits that shape a world, not really being a part of it. None of them really interesting protagonists or good for telling a connected story. Great side-characters that pop up in someone elses story and make those stories more interesting, if they were interesting in the first place (which is my issue with the Bard/Kindred/Kalista stories...).

Why are these mythical figures playable characters in the first place?

More mythological type champions, champions which lore stretches through numerous centuries and have shaped the Runeterra as it is or are aspects of the natural world itself (like nature gods/ spirits from pagan mythology).

Life, presumably.

is Life. is Preserve. Kindred is Death.

Hopefully the de-powering of said death and reveal that Kindred isn't actually death per-say, just an unbelievably powerful being that took its title.

I would personally love to see a Xerath vs Kindred or maybe an Urgot vs Kindred story where Kindred would be forced to flee. Although I really dig the new writing style and quality, I can't help but to think the Lore Team's over-mystifying their lore. I liked the new lore better because there are few fantasy stories out there in which Man is the most powerful creature. I'd like to see Humanity regain some of its lost control over the world of Runeterra.

Where? To boldly go where no man has gone before

i'm curious as to why Kindred spared Gangplank, considering they'd "met" after he almost died

what makes them decide who dies, and when?

what relation do they have with other beings like Bard or Soraka? How do they interact? Are Tahm and Aatrox on their level of power?

A theory I have is that we might be getting the Seven Deadly Sins. Lets think of the more supernatural/godlike beings in Runeterra. Tahm Kench obviously represents Gluttony, with his constant need for comsumption. Aatrox being Wrath, no need to explain why. Xerath could possibly be Greed, as he was willing to go any lengths to achieve Ascension. Azir himself could also possible be Pride, because lets face it, he is pretty egocentric. Im sure that more can be found if you look, but this is what I came up with from the top of my mind. There are also the unknown Darkin (Here we are disregarding the Darkin theory with Jax/Varus, though Jax could be Pride considering how he is so skilled with a weapon that he isnt allowed to use it, and the whole "Who wants a piece of the champ?" thing, but now Im getting off track) could also be representing the Sins as Aatrox represent one of them. There might also be future champs for the rest of the sins, but what do I know. Its just a theory that might have some truth to it.

I'm guessing it's going to be one of those stories where everyone dies at the end......Like SPOILERS!!!!! for example.

i think there will be a magical quest started by bard convincing champions to find the legendary dragon ao shin this story is coming soon (tm)