This is perhaps not entirely but possibly largely a reference to the "final boss" of Yukari Quest, which was a bizarre combination of a forgotten tree deity and millions of unused memories from Utsuho Quest's Gensokyo Isle (which is where Stargazer first appeared) as well as possibly components of The Construct from Reisen Quest. Given you are talking to Yukari, it may be worth describing these things; the "Reaching, always reaching" in particular is likely to set something off inside her mind.
// Indeed those characteristics correspond so far with the discoveries made together with Parchouli,Suwako and Doremy //
// In addition, "Unseen Clergy's Manner of (Un)Showing and Mode of Operation " really seem to be linked to the "Final Warning of "Sakuya Quest A-Z":"Beware the Formless One"; at its very end ,with Sakuya consulting and explaining with Yukari, the Mystery of "A Part of the Timeline Disappeared,Not Seemingly Existing Anymore" appeared //
//This also correspond with a Sakuya(who should be on our "Priority Encounter List") still in Activity about That and still Exchanging Help with Yukari(whom Sakuya visited earlier again but she is not gong do so for a while,as Ran commented)//
>The response is another dense bundle of feelings. You can feel...crowding...intrusion...heat, anger; desire. Reaching, always reaching. Things that don't make sense. There's more in the bundle, buried too deep to really sense, but it just leaves you feeling confused.
>_
> " Mmmh...is the most standing-out and more clear "Happenings by Those Someones"to you,Stargazer,that"Reaching,always reaching" or something,or even somethings,else?"