In some ways I’m cheating by using Yves to kick off my Angelic Ascendancy series because I tend to think that the default setting is an Yves ascendant setting. Only Michael is hostile to Yves, and even he respects Yves command to avoid interfering with free will where possible.
And it’s not just men who have free will and whom heaven nudges towards their Destiny, Celestials also enjoy that privilege (if they did not, there would be no fallen).
The Grand Academy
One way to increase Yves influence is to extend his metaphor throughout the whole of heaven. While many Superiors would still use Cathedrals and Mosques (they are, after all, places of learning), taken as a whole heaven would feel like a massive college town. Lecture halls, agora, and dormitories would sprawl throughout every domain. Trusted Masters could hold Higher Distinctions as Deans or Provosts within their respective words, and Yves would elevate Scholars and Philosophers from throughout heaven, not just his own Servitors (see Superiors III p 108).
Yves would probably serve as either Head of School or Chairman of the Board depending on whether you want him exerting direct control over the activities of heaven or merely acting as a “senior adviser” capable of having the head replaced should he find sufficient cause. Personally, I prefer the latter option because it seems most similar to what already exists.
Given the more formal structure a scholastic metaphor would impose upon heaven, relations with Jordi and Janus would probably be cooler. On the other hand Lawrence and Jean would probably find the arrangement quite satisfactory.
The Illusion of Free Will
Another option (if you prefer a low-to-no-contrast game) is that Yves is god’s will, and that god has left nothing to chance. Heaven and all the conflicts within it were planned by god from the beginning. Same with Hell. Damnation, redemption, and free will are effectively illusions even if they do not feel that way from within.
Yves influence in this version would be difficult to perceive unless things somehow go off script. And the stronger he is the less likely that is to happen. However, this version of Yves would have the ability to call on the services of almost any Celestial Superior (even some of the Superiors of Hell, though they might not realize it’s Yves calling the shots). He can also lie with impunity, and routinely espouses goals that differ vastly from his true objectives so long as his lies push the Symphony in the direction its supposed to go.
This would be a good variation for an Etherials vs. Celestials game, a heavenly paranoid distopia, or even a “lone voice vs the machine” story starring the Servitors of Eli, Kronos, or Lucifer (though it’s entirely possible that Kronos is Yves in this version of the setting).
However, the variation that is closest to canon is that Yves is part of “upper management.” Perhaps he’s an angel from the higher heavens, or an aspect of god, or a heavenly consort formed from gods rib. Regardless of what Yves is, his purpose is to act as a Superior to the Archangels, just as they serve as Superiors to the Angels.
However you have him act towards his Servitors, is also basically how he acts towards the other Archangels. Most likely this means he’s the wise old uncle who encourages them to ask for help when necessary, and perhaps volunteers advice when it seems appropriate, but who rarely interferes or compels. Even though he is the shepherd of destiny – in the core setting he is In Nomine’s largest champion for free will.
In this variation the Seraphim Council would have the ability to go against Yves, but it would rarely do so since most of the members actively turn to the old angel for advice. Even when they do rule against him, it will probably be because they consider his current requests run counter to his previous guidance.
This Yves may even have the ability to Wordbind angels all on his own, but no one would ever know because he has no reason to work around the Council. Even if they disagree with him on other matters, the naming of Wordbound is practically a given since the naming of things was one of Yves first confirmed responsibilities.
As with the first Yves Ascendant variation, this version of Yves would probably grant the Scholar and Philosopher Distinctions to especially notable Celestials serving under other Archangels. The Distinction gives no mechanical ability, but does grant the Angel speaking rights within Yves various philosophical assemblies.