Outward is a fairly obtuse game - one that's intent on letting players figure things out as they go along. This is quite charming in and of itself, but some of the game's more complex puzzles, such as Outward Corrupted Tomb, aren't to be trifled with.
If you've already made your way to the Corrupted Tomb, you've probably noticed that Myriade, the resident "NPC", needs your help with cleansing the place of the infection. This isn't quite as straightforward as it might first seem.
Outward Corrupted Tomb Quest
Information about completing the Corrupted Tomb quest in Outward is rather scarce, though we've been able to learn some key tidbits from players who've already plowed through the game.
For example, the reason you can't simply help Myriade with cleansing the Corrupted Tomb is that this particular side-gig relates heavily to the Holy Mission questline, so if you want to progress with Myriade, you're going to have to take that up and get through it a fair bit.
Before that's done, you can't really do much else in the Corrupted Tomb short of contending with Wendigos and looting chests, which isn't a bad deal either, all things considered.