[Discussion] If The Long Quiet and The Shifting Mound (Slay The Princess) could grant Authorities, how strong/powerful would they be and how would they appear?

To be more specific: assuming The Long Quiet and The Shifting Mound were entities in Lugunica and could maybe inflict their own specific kind of Witch Factor upon the world, how and on whom do you think it would manifest? A short summarization for those who haven played the game: The Shifting Mound is the literal embodiment of the concept of change and transformation. Originally she was a part of the cycle of life and death, but eventually a mortal who feared the end of his world decided to tear the cycle apart and created her with the intention to remove the concept of death or rather the end. As she is the literal embodiment of the concept of change and transformation, The Shifting Mound holds domain over everything that causes a change. This also includes death and destruction as these concepts are crucial to the creation of something.
The Long Quiet meanwhile is the other part of the cycle created by Narrator. He is the literal embodiment of stagnation, void and nothingness. If The Shifting Mound is transformation and change, The Long Quiet is the pause between these changes. A world without him would mean constant changing non-stop. There would be no pause or breath to witness or enjoy the change. On the other hand, a world without The Shifting Mound would be a stagnant one where nothing would happen at all. It's also why the Narrator created him, as The Long Quiet's original purpose is to kill The Shifting Mound and remove the concept of change, and with it the concept of death as well, permanently.
This was a rough summarization about them.
Personally, I think if these two were entities in the world of Re:Zero, then imagine that their authorities would manifest on the most ambitious and most narrow minded people. An ambitious person would get the Authority of Change while a narrow minded person would get the Authority of Stagnation. I mean, it would make sense, right? A very ambitious person would always try to change the world for his own gains be it good or bad. Meanwhile a narrow minded or extremely pessimistic person would rather prefer stagnation over change, as change wouldn't necessarily turn something into the better. From their point of view at least. As for the powers, I imagine that the Authority granted by The Shifting Mound would extremely vary from person to person. In the Long Quiet's case I'm not sure though. Perhaps it would be similar to Regulus's power? Or some kind of existence erasure? Maybe it would be a kind of being alive and not alive in the same time? No idea to be honest.
Anyway, I just thought about this game while watching Re:Zero and found that their are some similarities between these two. So I thought it could be interesting to discuss this hypothetical what-if scenario.
What do you think? Oh and also, assuming Subaru would somehow manifest both authorities of them in himself, how would he use them? And do you think they would be weaker or stronger under Subaru as their bearer?