It depends.
Both are found near the start of the game.
Kilowattrel has amazing Speed and good Special Attack. Its move pool is very limited, however, with the only non-STAB special moves it gets being Normal-type. Its STABs are normally enough, but if you run into something that resists both, you'll be forced to switch. Its abilities are alright, though I would recommend Volt Absorb rather than Wind Power due to Wind Power being situational. If you want to use Wind Power, then use it with Tailwind as it gets the boost from it.
Pawmot has good Attack and Speed, and a better move pool to work with, getting the Elemental punches and Bulk Up. Also, I'm not sure if this is how Double Shock works so don't quote me on this, but I believe that if you Terastilize into an Electric-type, then you can use Double Shock endlessly. It also gets Revival Blessing, which may not be useful when you can use items in-game, but if you restrict yourself from doing so then it could prove useful. Its abilities are pretty useful as well, with Volt Absorb allowing you to switch in against electric types more easily and Natural Cure allowing you to not be completely crippled by a status condition. Fighting is also a better offensive type than Flying.
My choice would be Pawmot due to its wider move pool and better offensive typing than Kilowattrel.
A set for Pawmot would be:
Pawmot @ Punching Glove/ Magnet
Ability: Natural Cure/ Volt Absorb
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Double Shock/ Thunder Punch
- Close Combat/ Brick Break
- Bulk Up
- Ice Punch
Use Thunder Punch if you won't Terastilise Electric (Or if the Double Shock thing doesn't work lmao)
Use Brick Break if you're concerned about PP or the defense drops.
If you really want to use Kilowattrel (or if you chose Quaquaval as your starter or have any other Fighting types), then you can use this set:
Kilowattrel @ Magnet/ Sharp Beak
Ability: Wind Power/ Volt Absorb
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Thunderbolt
- Air Slash
- Tailwind
- Thunder Wave/ Volt Switch
Tailwind would be a good support move even if you opt for Volt Absorb. Thunder Wave can help catch Pokemon or cripple something that would be a threat. Volt Switch can be used if you want to do a bit of damage to something before switching.
Hope this helps.