Basically bringing back Disguiser V2, but more powerful than ever before through giving it manual selection (and letting it still do its Disguiser V3 thing). That is, give it the ability to, at any time, pick a role out of a list (your real Will will be used in any case). If it dies for any reason, it will appear to be the most recent role it selected in the Graveyard.
Right now it's nothing but a terrible hard counter that can actively screw the Mafia solely by it being known that it exists in the round. This ability could, in addition to never letting the word "Disguiser" appear in the Graveyard at all, be used either to provide an explanation for why someone was repeatedly getting visited by the Mafia (coordinate with them in Night Chat to have them pretend to be Blackmailed/roleblocked every night you visit them and set your Self Forge as Blackmailer/Consort so that if you die, their story seems to check out, just make sure you don't try this with the Mafioso or solo Godfather or else you'll blow your cover because of Mafia kills not appearing to be visited, though this is still flawed because if they go down before you, the Spy will become sure there was a Disguiser, though if you camped the other RM exclusively this can be mitigated since they won't be able to pin any other Mafia) or to simply screw up the Graveyard (set your self-forge to your claim if you get lynched so the town thinks they mislynched, or set it to Godfather to disperse some heat toward the real ones).
To prevent this from getting ruined up by an Investigator really easily, your Investigator result will always match your current self-Forge. (So if you get Investigated while you've chosen Consort, an Investigator will see you as Escort/Transporter/Consort/Hypnotist). Be careful to not get investigated, change your self-Forge, then get investigated again or that'll spill your real role since the result is suddenly different with no explanation.