I suggest you use these three together, because they work off each other so well
AronUGonnaForfeit? (Aron) @ Shell Bell
Ability: Sturdy
Level: 1
EVs: 69 HP / 69 Atk / 69 Def / 69 SpA / 69 SpD / 69 Spe
Naive Nature
IVs: 0 HP / 0 Def / 0 SpD
- Endeavor
- Protect
- Stealth Rock
- Toxic / Body Slam
The classic F.E.A.R Aron. Endeavor + Shell Bell allows it to recover to full HP. Protect is for scouting, and Stealth Rock is for setting up spikes (unless they're already set). Toxic is for status and is practically filler, while Body Slam is for a 30% chance for paralysis. 0 IVs in Aron's defensive stats are to ensure Sturdy activates as we all know Level 1 Pokemon have extraordinary bulk, and the EV spread is because humor. Don't worry, the EV spread only increases Aron's speed by 1.
Ctrl+W, Ctrl+F4 (Togedemaru) @ Shell Bell
Ability: Sturdy
Level: 1
EVs: 69 HP / 69 Atk / 69 Def / 69 SpA / 69 SpD / 69 Spe
Naive Nature
IVs: 0 HP / 0 Def / 0 SpD
- Nuzzle
- Spiky Shield
- Endeavor
- Fake Out
This set works similar towards Arons, and can be used as backup if it faints. Endeavor + Shell Bell allows Togedemaru to recover to full health. Spiky Shield allows for scouting, and can knock out anything that you've used Endeavor on and makes contact. Nuzzle guarantees paralysis, allowing Togedemaru to somewhat assist its team members. Fake Out is if you safely swap in Togedemaru after Aron used Endeavor, allowing it to finish off the foes Pokemon unharmed, as well as to help render any Focus Sashes on the opponents team useless. Once again, the EV spread is in good humor, and the IV spread insures Sturdy activates.
GigaIrritation (Gigalith) @ Smooth Rock
Ability: Sand Stream
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Explosion
- Stealth Rock
- Rock Slide
- Sandstorm
Gigalith's Sand Stream sets up Sandstorm, which allows Pokemon who have already been weakened down by Aron and Togedemaru to get knocked out. Explosion allows you to safely switch in Aron and Togedemaru, and to deal a bit of additional damage. Rock Slide and Sandstorm are mostly filler, but they provide a STAB move as well as being able to set back up Sandstorm without switch Gigalith in and out of battle. Stealth Rock for additional damage. You may also have other Sand Stream users, but as this was designed for lower tier, I haven't included the likes of Hippowdon and Tyranitar.
This trio can be easily countered by Dynamaxed mons and Rock/Ground/Steel types, so make sure you have several other team members who can deal with them.