For people confused, theyre in a cultivation world and it's a common trope that in order for a cultivator (the main lead here) to break through to the next level or "ascend" they must pass heavenly tribulations bc most cultivators aim for immortality. This is usually in the form of lightning strikes. But anyways, the cultivator has to survive the strikes and once they do, they get rewards like body strengthening etc. So that's what the main lead is doing here! It's pretty funny to read world hopping novels like this because they're so meta and have a lot of references to chinese web novel tropes.