This is shown with Atou's betrayal. In D&D rule you can make anyone an ally but not if you force them to kill their loves one or their important people.
A net 20 isn't going to help you if you force a husband to kill a wife. They will instead ask if you are sure? Upon confirmation, the husband will instantly betray you...
You actually can, but you need to "help" them rationalize the act.
This is not like magic that makes the target rationalize his actions or ignore his will entirely, this is a discussion where you convince someone with arguments. It can be either logical or emotional arguments, but it is most definitely
not just "roll a dice and it works". Any GM that lets a player roll persuasion without at least a base reason for it is just letting the player abuse the system willfully. The roll is just supposed to see how well the character argues the case, but the baseline for the case must come from the player.
In your example, you can try to insinuate that the spouse was abusive or unfaithful,
then push for murder.
Going straight for "please murder your loving spouse - rolls nat20 - Oh, ok" is just bad RP.
Much like ignoring combat rules and making a scripted scene that kills a much stronger opponent instead. Worse yet by involving other characters that 1. don't belong to your game and 2. weren't even at the scene to begin with.
In this case, there seemed to be no discussion to even pretend that there was an attempt at persuasion.
And it seems like there was no attempt to pretend that the result to chanced. The witch character talked like a nat20 is expected on every roll. The GM antagonist just cheated, plain and simple.
So this dumbass of a god of D&D doesn't even know his own rule. He's just as shocking as evidence that he no longer gives any guides to his own followers when that happens.
Knowing the rules and abusing them are two different things.
Another people already said before that the player can't die until all chance of reversing the game has been destroyed AKA all city or bases.
If that's how it goes, This MC is pretty much invulnerable as long as his faction stands.
Maybe down to the very last individual, which can make him very hard to kill.
Basically, it's the same system as some fantasy fictions where a god can only be killed by eradicating their religion, down to the last believer.
That would be quite an abuse of the system in itself though, as the leader of a RTS faction doesn't act on their own. They are supposed to conduct war through units built or summoned by the game rules. Which is what he was doing until he got attacked directly, through an abuse of a different system.
Basically, the RTS leader's immortality comes from normally not
directly participating in the game. In cases where they do, their defeat isn't impossible and it generally marks the defeat of his whole faction, similar to capturing the king in chess.
So the D&D god is written as "dumb" not that the author doesn't know the rule.
100% in agreement.
Judging a character and criticizing the writing are two different things.