There aren’t many resources (other then SC wiki) dedicated to SC lore- and story- related themes. But just recently I stumbled upon Youtube channel that covers these – and even more.
Now I don’t know whether you know Mark Yoons channel already or not. To me, his name was new and his content surprising.
Mark Yoon on his Youtube channel is not covering only SC but also other fighting games; but SC seems to be in the centre of his interest (what he confirms in his latest video).
And when I say SoulCalibur, I don’t mean “usual” stuff like tournament VODs, combo videos or guides. No. He focus on game lore and history; as well as creations, theories and news.
And if you actually dig into his content, you may be surprised what you find.
For example, one of his later videos talks about Iska Acht, the mysterious girl from DLC13 story. He links her to sources from other games and characters, explains who she (probably) is and adds some well-explained theories about her further place in SC storyline (and eventually, select screen and further games).
Overall, if you enjoy SC not only for its competitive content but also through the lore, story and characters..? I highly recommend you to check Mark Yoons channel and eventually, to give him a subscribe!