The Rings or whatever we are making are vessels in theory the spell to make them Essence 5 combines with their Soul as a additional piece of them. The ring is simply a manifestation of that.
We are sticking the powerup to their Souls and having whatever can be taken on/off as symbols of that Gift.
The Ring itself can likely act as a External Pool as they are God-Blooded and in actuality only have one pool.
...we CAN'T give them a second essence pool, we can't make baby Exalts that's the sort of shit that we need Auto-Kun for, seriously that's hard coded into the setting
Mittelt has one pool, just like everyone else, other then us, which is only a thing because we are an Exalt, even Sol Invictus has one freaking Essence Pool, they don't need more then one without needing a stealth pool to keep from flaring there anima banner and as we are not giving them that stupid thing *worst handicap ever* it doesn't matter
making something manifest to show the enhancement is silly and tactically unsound, not to mention a opens things up for some sort of BS to come along and de-power them in the future, all we need is some SG that lets someone steal anything they can see and make it there own as long as it's not another SG and they be fucked and we have a seriously dangerous enemy on our hands (this is exactly what I would do to fuck us over if it was me and you were pulling something like this items tied to power-ups are a horrible idea particularly if they are visible any time after they are used for the first time
seriously this sort of stuff is the reason I thought a Blank Card would be a better base unit, Issei and whoever charge the which creates the link, Alexander picks whatever Major Arcana he figures works best for the character and gives them Epic Attribute boosts in line with that, and leave it open for in the future for them to have a BB type moment where they manafest another card for more power if need be, simple, easy, the basic card set to give a flat 1 dot buff to Stamina, Dexterity and Wits (because those are the most important combat stats)
no muse no fuse, no retarded votes every time someone gets empowered and best of all, and stupid bling, honestly I'd have used playing cards only the Angels do that and that would limit us, this way we can have a major empowerment with the Major Arcana Blank cards and a lesser Empowerment with a Minor Arcana Card if we want /shrug
but I doubt everyone else if going to agree with that, which is why I didn't bring it up again until now