If a creature is True Polymorphed into a Wight that uses its Life Drain ability to raise zombies, do they stay controlled if True Polymorph ends?

Question

Say you have a high-level wizard that can cast True Polymorph, and they turn into a Wight. They then use the Wight's Life Drain action, and manage to create a few zombies. Let's assume the Wizard does not maintain concentration for the full duration, so the True Polymorph is not permanent.

Do the zombies remain under the wizard's permanent control once the True Polymorph spell wears off (or is dispelled)?

I would prefer something concrete from the rules that would provide a definitive answer on this, but I also understand if it comes down to "DM's choice."

As a side note, this is for my very first campaign as a DM that will be starting up soonish, and the group I play with are very creative in their tomfoolery, so I am expecting one of them to try something along these lines.

Answer 1

DM's Choice

I scoured the Monster Manual and PHB and couldn't find anything related to this issue specifically, so I would say that it's the DM's choice on whether this works or not.

If you are a player, ask the DM whether this will work, and take what they say as correct.

If you are a DM, here's what I would suggest: If they have any spells or effects allowing them to control undead, such as Animate Dead, they can use those spells or effect to maintain control over the zombies; otherwise, they lose control of the zombies and they either attack the former wight or die immediately. Ultimately, it is the DM's choice how to handle this situation.

Answer 2

The Player retains control

The text of the Wight's Life Drain reads

A humanoid slain by this attack rises 24 hours later as a zombie under the wight's control, unless the humanoid is restored to life or its body is destroyed.

There is no indication that the Wight needs to maintain any kind of concentration or channeling to keep this effect going. It is just a side effect of the attack. By RAW there is nothing to indicate that it should end. There is nothing in RAW to even suggest that killing the Wight would kill the zombies.

For a more extreme example of effects lasting beyond their user's ability to create them, check out this thread Do your spells end when you die? (Note: I don't think Life Drain is a spell, but it follows the same logic)

If this is happening in your game now, and you decide not to let them have the zombies, you should talk to them. They may already have the idea that they get the zombies. For them it could be quite disheartening to hear that the DM had gone to SE and been advised that they can do whatever they want, contrary to the player's expectations. Remember that the rules allow players to have expectations about how their actions will interact with the world, it allows the players to think and plan.