If you are looking to stall in NU, I can honestly say this is one of your best allies:
Gourgeist-Small @ Leftovers
Ability: Frisk
EVs: 152 HP / 116 Def / 240 Spd
Jolly Nature
- Substitute
- Leech Seed
- Will-O-Wisp
- Rock Slide
You can build your entire team around this, and it can do some serious work. Contrary to popular belief, which is 'what do SubSeeders even do / stall out?', it is more 'what can it
not stall out?' in the case of Gourgeist-Small (which I will refer to as SmallGeist from now on). Sure it isn't unstoppable, but if your opponents lack the right responses and gives it a free turn it can very well near be. You get that free Substitute, and you are set to harass the shit out of your opponent; I have swung entire games around with this dude alone. It even spinblocks hazards, how cool is that shit?
The Speed investment allows SmallGeist to outrun Sigilyph, the next fastest Pokemon immune to its shenanigans, while also outspeeding Xatu. The HP and Defense investment are arranged so that SmallGeist can make 5 Substitutes (without Leech Seed recovery) while granting it the best overall physical bulk, such that Virizion's Stone Edges have only a miniscule chance of breaking its Sub. SubSeed + Wisp are standard fare for SmallGeist, and what makes it unique is that as a SubSeeder, it can annoy Grass-types with Will-O-Wisp; as a Wisp user, it can plant Leech Seed on Fire-types to give it and its teammates an easier time. My attacking move of choice is, surprisingly, unSTABed Rock Slide, but it is ridiculously perfect in covering problematic threats, such as Xatu, Sigilyph, Fire-types, Cryogonal, and
Chatot.
SmallGeist does have its share of problems though, as Toxic Spikes and Sticky Web can really mess it up, and opponents such as Chatter Chatot and Infiltrator Spiritomb can target it behind its Sub, Grass-type Aromatherapy users can be really annoying (especially those that can strike back, so Vileplume > Meganium to combat SmallGeist), and of course you'll want a good Fire-type switch-in considering their ubiquity. Other benefits to SmallGeist include cleric and hazard support. That said, SmallGeist is a truly effective staller, and is one of stall's main edges over other playstyles: I'd even go to say it is the
cornerstone of stall (may or may not be exaggeration).