Shiny Aegislash. It's crimson color is bold and beautiful, and also has a poetic symbolism to it- a sword red with blood from the countless intrigues and battles it saw throughout the ages. The color really emphasizes it's ghost typing, and association with death. It's just a great favorite of mine.
The honedge line isn't in Scarlet and Violet, so I would have to go back to an older game to try this hunt. It would be a good pokemon to breed for with the Masuda Method, but I prefer to catch shinies in the wild, and unfortunately, you see this pokemon in the wild very little. It will be pretty much limited to a particular place within a region, and often can only appear under some gimmicky circumstance like during certain weather conditions in Galar, or using the island scan on a special day of the week in Alola. It's still doable, but a full odds shiny honedge or doublade is something I just don't think I am ready to go looking for yet, breathtaking as it is.