Mordenkainens Tome of Foes introducerade Dybbuk, en snygg CR 4 Medium fiend (demon) med en särskild förmåga:

Possess Corpse (Recharge 6). The dybbuk disappears into an intact corpse it can see within 5 feet of it. The corpse must be Large or smaller and be that of a beast or a humanoid. The dybbuk is now effectively the possessed creature.

[...]

While possessing the corpse, the dybbuk retains its hit points, alignment, Intelligence, Wisdom, Charisma, telepathy, and immunity to poison damage, exhaustion, and being charmed and frightened. It otherwise uses the possessed target's game statistics, gaining access to its knowledge and proficiencies but not its class features, if any.

[...]

Så jag får det att en besatt PC-paladin skulle kunna slå som vanligt med sitt svärd (samma STR och kompetens), men inte använda Divine Smite eller Lay on Hand, eftersom de är klassfunktioner.