>>23147001lightningrod. He has great base attack even without investment, and can many take hits like a champ albeit if they aren't water or grass.
Before I ran these numbers I played around with 120hp/136def/252spD set vs. 120hp/136at/252spD set. The results were not that different, mostly by ~5%
>136 Atk Rhydon Drill Run vs. 4 HP / 0 Def Terrakion: 138-164 (82.6 - 98.2%) -- guaranteed 2HKO>60 SpA Rotom-W Hydro Pump vs. 120 HP / 252+ SpD Eviolite Rhydon: 208-252 (106.6 - 129.2%) -- guaranteed OHKO(don't even think of trying to live that)
>252+ Atk Life Orb Bisharp Iron Head vs. 120 HP / 0 Def Eviolite Rhydon: 109-133 (55.8 - 68.2%) -- guaranteed 2HKOor if you prefer defense over attack
>252+ Atk Life Orb Bisharp Iron Head vs. 120 HP / 136 Def Eviolite Rhydon: 101-120 (51.7 - 61.5%) -- guaranteed 2HKO>252+ SpA Choice Specs Pixilate Sylveon Hyper Voice vs. 120 HP / 252+ SpD Eviolite Rhydon: 84-99 (43 - 50.7%) -- 2.7% chance to 2HKO>252+ SpA Choice Specs Pixilate Sylveon Hyper Beam vs. 120 HP / 252+ SpD Eviolite Rhydon: 186-219 (95.3 - 112.3%) -- 68.8% chance to OHKOOn the off chance the enemy runs one of these
The irony is that Mantine works beautifully with lightningrod support but many lightningrodders don't seem to have much use of tailwind. I'm at a wall here.
