>>53572841>>53572894It's actually worse than you say. If Chesaught genuinely beat Kingambit, it would have a respectable niche: imagine a Spikes setter that sits on most Great Tusk/Meowscarada all day, countered Kingambit, and gave you a solid switch-in to Brute Bonnet and Floatzel in their respective weathers.
But if Kingambit Teras into basically any type, then Chesnaught turns into setup fodder. Even Tera Dark lives three Drain Punches.
Terastalization is a net negative for Chesnaught, which already had problems with 4MSS and being passive before everything could choose to resist Drain Punch on a whim. Good luck ever slotting Leech Seed + Spiky Shield again, now you probably want at least two of Drain Punch/Wood Hammer/Roar/Taunt as well as Spikes.