Tetractys
First let me open by stating A.) I wrote a whole bunch but accidently clicked Create A Discussion and erased it all. B.) This is using Jhin as a stepping stool.
I'm personally displeased with the culmination of Jhin's theme. Not that the theme is in itself bad, I think that's very nice. But it didn't click well with what mechanics were given to him. But that doesn't mean all hope is lost. You see, a musician isn't someone who can play the guitar. An artists isn't someone who can paint a picture. Those are guitarists and painters. The Virtuoso, likewise, shouldn't be defined by his pretty particle effects or mechanically slow for the purpose of perceived critical decisions. No, instead I'll take the teasers and trailers and use that as a basis for his being the progenitor of Tetractys.
You see, a Tetractys is the divine symbol worshiped by Pythagoreans. It is a mathematical representation of the universe which very elegantly finds itself in the fields of art, music, and science. The history is the subject of books, so I'll be brief. 4 skill slots, 4 rows to the tetractys, 4 champion teaser icons. Monad, Dyad, Tertiad, Tetrad. Garen/Monad/Unity. Vi/Dyad/Power. Sona/Tertiad/Harmony. Zed/Tetrad/Kosmos.
As the Virtuoso, his targets had wonderful gifts that were squandered in their own right. So he used them to create the tetractys. As a passive, there is the decad which is the culmination of all 4 points. 1+2+3+4 = 10. Likewise, in the sense of the E being Harmony, you have the ratios of the 4 rows of the tetractys (it's a triangle, look it up) which is 4:3 the Perfect Fourth, 3:2 the Perfect Fifth, and 2:1 Octave. This point I'm not very clear on given the musical nature of it, but it's supported nonetheless. I understand Kosmos is more likened to Order, but it's really the universe and all it's constituents. As Zed is from Ionia, in spite of his chaotic nature and Yin/Yang theme, that very theme is in line with the nature of balance and the universe, there being no permanence in any state.
Virtuoso is obsessed with his art. With beauty. But he himself will never achieve perfection. Those sacrifices were paint on the palette for Tetractys. The others shot? Other works. Not everything goes into the magnum opus.