If he does play Hades, there's not really much you can do to get handheld through it, at least not in my experience with it. The best his fans might be able to do is to tell him what weapons are easiest to use, but even then it's mostly preference. The game is beatable with all of the weapons available, and some synergize better with different blessings. There's not much a guide could even really tell you outside of some basic strategy, or advice on which blessings to take if they're offered.
If he plays Hades, we're going to get Returnal 2.0 bitching. He might even use Returnal as an example of what a good rougelike looks like when he starts getting his ass kicked by mini-bosses or normal rooms.
I can't wait for him to meet the hydra for the first time, that cocksucker too me ages to beat the first time.