Two rounds: nen and curse/cursed energy are visible to both sides, and not. Feel free to mix and match if you see a better match up. And you can do 1v1s or team battles with each subgroup
Main on Main
Gon Freecss (with nen) vs Yuji Itadora
Kurapika vs Megumi Fushiguro
Leorio vs Nobara Kugisaki
Killua Zoldyck vs Papaguro (OK he isn't a main but he's the best match up I could think of for Godspeed)
Chimera Ants vs Special Grades
Peak Meurem vs Sukuna
Menthuthuyoupi vs Mahito
Neferpitou vs Hanami
Actual Cannibal Shaiapouf vs Dagon
Cheetu vs Jogo
Phantom Troupe vs Sorcerers
Chrollo Lucifer vs Suguru Geto
Nobunaga Hazama vs Composite New Shadow Simple Domain user (none have a ton of feats I recall)
Feitan Portorvs vs Naobito Zenin
Machi Komacine vs Toge Inumaki
Hisoka Morow vs Aoi Todo
Phinks Magcub vs Kento Nanami
Shalnak vs Mei Mei
Franklin Bordeau vs Ryu Ishigori
Shizuku Murasaki vs Reggie Star
Bonolenov Ndongo vs Takuma Ino
Uvogin vs Kinji Hakari
Illumi Zoldyck vs Yuta Okkotsu