5e Homebrew - Lingering Soul class question

[Haunted Panda]

Technically, this is a question about how to handle a homebrewed class... but the question has some standard ruleset implications, so I figured I'd ask here.

So, the Lingering Soul class has an ability that allows the character to possess another creature as a bonus action. Then, they can use their action to force them to do a number of things. One of these thing is make them perform a weapon attack.

My question is, what if they made the possessed creature do a weapon attack on themselves? How would that be treated? Like a normal attack where they still roll to hit? Or would it auto-hit?

Does it do normal damage? Critical damage? Instant KO? Does it depend on the description of the attack in question?

[orcbane]

1. I would say that the possessed creature would almost certainly be granted an extra saving throw to overcome this action, likely with Advantage.

2. I would limit this kind of thing to Evil-aligned characters. It certainly wouldn't be available to Good-aligned characters in one of my campaigns.

3. I would likely enforce some sort of shared damage between the possessor and possessed.

4. Here are the Coup de Grace rules from 3.5. You may find them helpful for this scenario.

Coup de Grace
As a full-round action, you can use a melee weapon to deliver a coup de grace to a helpless opponent. You can also use a bow or crossbow, provided you are adjacent to the target.

You automatically hit and score a critical hit. If the defender survives the damage, he must make a Fortitude save (DC 10 + damage dealt) or die. A rogue also gets her extra sneak attack damage against a helpless opponent when delivering a coup de grace.

Delivering a coup de grace provokes attacks of opportunity from threatening opponents.

You can’t deliver a coup de grace against a creature that is immune to critical hits. You can deliver a coup de grace against a creature with total concealment, but doing this requires two consecutive full-round actions (one to "find" the creature once you’ve determined what square it’s in, and one to deliver the coup de grace).

[jj_wolven]

homebrewed classes are difficult to deal with as a GM. Most end up being too powerful, though some are too weak when they are over-themed.

We used to have a section on the website that was the Official Sourcebook of RPGCrossing, but we didn't get enough entries so it faded out. I ran it and had a vetted selection of judges to balance anything submitted.

We also have the Houserules and Custom Option thread. That section gives opinions but doesn't really balance things.

-me