I would also be glad to see the Sanctuary faction in the third Heroes game.

Exactly. Perhaps, Sanctuary is one of the best additions since the fourth game. I think Sanctuary could fit very harmoniously into the world of the third game, but it would be nice to reduce the Asian flavor in the names of the creatures. It wouldn't take long to change them, for example, Kappa / Poisonous Kappa, Mermaid / Undine, Shark Guard / Shark Warrior, River Spirit / Nereid, Daughter of Winter / Yuki-Onna, Sea Naga / Ocean Naga, Qilin / Kirin. Why shouldn't the names of Kappa, Yuki-Onna, Qilin, and Kirin be changed: they are original, and there are, one might say, no analogues in other mythologies. It's a different matter with Mizu-Kami. I doubt that everyone knows that Mizu means water in Japanese, and Kami is a goddess...