Empoleon makes a great partner with Sceptile, at least in theory. Double resist to ice, resists all of Sceptile's other weaknesses, and has that immunity to poison, which means a safe switch on predicted toxics. In return, Sceptile's lightningrod protects from electric attacks. Empoleon can be used primarily as a pivot with defog/scald/toxic/filler, but because it has no reliable recovery this partnership kind of falls flat. Perhaps with wish passing or Healing Wish Latias this could be more viable, tbh I'm not the greatest teambuilder so I'm not sure how far this core could fly.