So assuming Tera functions as adaptability on same type forms... Normal Tera Dudunsparce
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Skarmory: 250-295 (74.8 - 88.3%)
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Blissey: 290-342 (40.6 - 47.8%) -- 59% chance to 2HKO after Stealth Rock
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 248+ SpD Hippowdon: 334-394 (79.5 - 93.8%) -- 6.3% chance to OHKO after Stealth Rock
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Toxapex: 276-326 (90.7 - 107.2%) -- guaranteed OHKO after Stealth Rock
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Ferrothorn: 165-195 (46.8 - 55.3%) -- 74.2% chance to 2HKO after Stealth Rock and Leftovers recovery
Still hits hard even once Tera gets Dynamax'd out of OU.
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Skarmory: 250-295 (74.8 - 88.3%)
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Blissey: 290-342 (40.6 - 47.8%) -- 59% chance to 2HKO after Stealth Rock
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 248+ SpD Hippowdon: 334-394 (79.5 - 93.8%) -- 6.3% chance to OHKO after Stealth Rock
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Toxapex: 276-326 (90.7 - 107.2%) -- guaranteed OHKO after Stealth Rock
252+ SpA Choice Specs Normal Tera Dudunsparce Boomburst vs. 252 HP / 4 SpD Ferrothorn: 165-195 (46.8 - 55.3%) -- 74.2% chance to 2HKO after Stealth Rock and Leftovers recovery
Still hits hard even once Tera gets Dynamax'd out of OU.