>>96310124
>>96304131
>Am I a bad DM for doing this?
Yes. Its the definition of a railroad
>The fight technically go either way but they'll almost definitely lose and be forced to go along with this.
You admitted that they have no chance of winning in your own post. Despite saying that it could go eitehr way, you didn't even give us an idea of what you would do if they succeeded. You know they won't.
>I want them to be able to level up and defeat these guys in a rematch later. Any ideas or advice?
pic related are shadowfell natives who could be using disguise self to appear as shadar kai, and it was the shadar kai who used a dream spell to intimidate the character and make them believe that these mooks are them. They'd be under orders from the three guys from the dream to assume their identity and force the players to drink the potion of compulsion (unironically a stupid idea, a magical contract for a lesser charm would be far more foreboding and fair, a dark deal forced on them.

If they are interested in free power, you could give them the shadow touched feat minus the ASI boost, and they could avoid the fight entirely. If you need other ideas for rewards, check the supernatural gits chapter on p277 in the 2014 dmg, and p98 in the 2024 dmg.