I'll just post this team and a calc (maybe you can make some adjustments to the team as I'm not really a good builder at all but the Inteleon set is heat)
https://pokepast.es/38af2c8e72471a79
252 SpA Sniper Inteleon Hyper Beam vs. 252 HP / 4 SpD Toxapex on a critical hit: 262-310 (86.1 - 101.9%) -- 93.8% chance to OHKO after Stealth Rock