Good news, gentlemen; I have leveled my very first Pokémon all the way to Level 100. Its Kartana- whom I specifically used in Pokémon League farming with a Lucky Egg.
I also, ironically, got my first Gold Bottle Cap through today's Poké Pelago mining, so I used it on Kartana. So not only is it Level 100- its IVs are also flawless.
Kartana@Focus Sash
Ability: Beast Boost
EVs: 252 Att, 4 Def, 252 Spe
Jolly Nature
Leaf Blade/Smart Strike/Psycho Cut/Sacred Sword
From my time using Kartana, I've determined two things. One, it doesn't need Swords Dance. After a boost from its ability, Kartana can slice up teams like paper. So I opted out of the Sweeper build and use an all-out attacker moveset instead, replacing Swords Dance with Psycho Cut.
Another thing is its Speed. Despite being pretty fast on its own, there's still multiple things that outspeed it. So in combination of Sticky Webs and Focus Sash, Kartana can outspeed or outlive these threats in order to continue its sweep. There are Pokémon that can't OHKO Kartana, for instance, certain Physical attackers, but the added survivability is still very comforting.