Garrus looks deeply hungover.

"I recognize that nothing could've prepared me for that, but a warning would still have been nice."

Jojo just looks a bit shellshocked.

"Yeah that was - uh - that was rude - what did it do -"

You are all more than you were. You have the seeds of divinity within you. You in particular now have capabilities exceeding those of anyone on your home planet who has not relinquished their mortality. Pause. With the possible exception of someone by the name of Baba Yaga. I do not know much about her, but she is also in possession of her own True Name. I do not know where she got it.

"...cool?" says Belmarniss blankly.

"We need Mephistopheles' True Name," Jojo says, getting back on track. "And the Reaper's."

Of course. I have not been ignorant of my former lover's transgressions... His Name is Thra'axfyl the Ambitious. And your Reaper is Hecugoth the Abandoned.

With each Name, there's a low thrum of power. Belmarniss can tell that these are not names one forgets.

It's probably rude or something to write them down so that's handy. "What can you tell us about using them?"

You will not be able to use them as generally as a more established power might. You can use your own Name to make changes to yourself, and the Names of others to control them... but Mephistopheles is still greater than you, and the Reaper almost as much so. You should still be able to command Mephistopheles to return to his rightful place. If you defeated him in combat and thereby weakened him, you could use it to quash his essence or to bend him to your will. Perhaps you could even take his power into yourself and make yourself the rightful queen of Cania. But I do not expect you to take that path.

"Not that it's not lovely for the right sort of occupant but yeah nah. Changes to myself like what?"

Natives of certain realms have curious properties. Given an example, you could shape your essence to use foreign abilities. Or accomplish other goals - some planes' denizens keep their souls outside their bodies in various forms, which you could also do. Pause. I do not recommend it. It would be hazardous in your current line of work.

"More so than keeping it in my body? Because that's already gotten me killed a few times."

The vague mental impression of a shrug. It is not without its advantages. But if you choose to do so, ensure that no one touches your soul while it is vulnerable. The consequences are dire, by all accounts. 

"Noted. So we just, what, walk up to Mephistopholes and tell him to fuck off, is this an exact words kind of deal, does he get a will save?"

Faint amusement. We are well beyond the realm of will saves. When you invoke a True Name, the effect is either within your power or outside it. Nothing more, nothing less. And you needn't worry about the exact words. He will know your meaning.

"What does quashing his essence mean?"

He would cease to be a part of the universe. Kill him, and he will reform in his palace in Mephistar. Quash his essence, and he will be gone forever, and a blow struck against Hell in the balance of Good and Evil.

"Gosh. Uh, in what ways am I more powerful now, like, am I just higher level and it merely feels weird to do that all at once, or...?"

You are higher level, as you say. You also have access to abilities in keeping with your new power - abilities which your home planet has never heard of, though this one has a handful of legendary heroes who have possessed them.

"Could you be more specific."

You could alter your magical channels so that you no longer need to speak or move in order to use magic. You could enhance spells above the ninth circle. You could learn the secrets of certain spells which are inherently beyond the ninth circle. You could - ah, your magic has already adapted to one such enhancement. You will find that where your spells needed the energy and structure of diamonds, before, and other such sacrificial materials, you may substitute your own power. Only to a limited extent; it will not afford you a free Wish, but it will allow... three Limited Wishes with a bit left over, per day. It is possible you could increase this limit, through practice and experience.

"...wow."

I do not give this power lightly. You bear the weight of destiny upon you, Truthseeker. I know you will do what must be done.

"Thank you."

Is there anything else you wish to ask?