Morpeko
- STAB attacks super effective against a few Pokemon in the Champion's Cup, including Hop's Corviknight and Leon's Aegislash
- Resists a few Pokemon in the Champion's Cup, like Hop's Corviknight
- Varied movepool
- Faster than Togedemaru (barely)
- Incredibly frail
Togedemaru
- STAB attacks super effective against Melony and a few Pokemon in the Champion's Cup, like Marnie's Grimmsarl and Hop's Corviknight
- Resists Melony's Ice moves, part of Raihan's team, and a few Pokemon in the Champion's Cup.
-Decent movepool
- Has a solid Attack stat
- Not as frail as Morpeko (but it's not the best defensively)
Either works well, so I'll give a moveset for each:
Morpeko @ Magnet / Black Glasses
Ability: Hunger Switch
- Aura Wheel
- Crunch
- Psychic Fangs
- Ice / Thunder / Fire Fang
Togedemaru @ Magnet / Metal Coat
Ability: Iron Barbs
- Wild Charge
- Poison Jab
- Iron Head
- Zen Headbutt
Hope I helped!