Demon diancie outdated, demon mew overrated,
demon registeel sucks long have we awaited, demon swampert activated.
Swampert @ Leftovers
Ability: Damp
Tera Type: Poison/Steel/Fairy
EVs: 252 HP / 40 Def / 216 SpD
Careful Nature
- Amnesia
- Bulk Up
- Knock Off
- Rest
Of all the "demon set" options (usually used to refer to a set that boosts both defense and tries to sweep) swampert has the best typing pre tera defensively only having a 4x weakness to grass and some useful resistances. The plan with this set is to have teammates take out immediate threats to its ability to set up, and get the pert rolling. The EV spread I went with a more SpDef biased spread, as though you boost faster with amnesia, often special attackers are used to try and pressure you first and you also want to be able to click bulk up more to boost your attack as well. Mono attack knock off as it allows swampert to have some utility before find a sweep opportunity as well as not having anything be immune to it, and 4x dark resists aren't very commonplace in the current meta. As knock off is the only attack torrent is useless thus we opt for damp since a 0.1% chance of being used is better than 0%. For tera types I mostly tried poison but steel and fairy have their defensive merits as well and will be up to preference.
For the team I went with I wanted to pair it with toxic spikes to help wear down bulkier mons that swampert would have a harder time muscling through, and specs sylveon felt like a nice pairing to bait poisons and steels that would be a thorn to toxic spikes with a strong psyshock/psychic or tera blast into tera blast ground.
NBT Swampert (pokepast.es)
Replays:
-
https://replay.pokemonshowdown.com/gen9nu-2116764804-gej0sk75j9wz4cxc4fxfvw1gajtdbm0pw
Also here is a funny calc I saw as I was trying this: 252 SpA Choice Specs Chandelure Energy Ball vs. +6 252 HP / 216+ SpD Swampert: 132-156 (32.6 - 38.6%) -- 1.9% chance to 3HKO after Leftovers recovery