>>39562459ngl your ideal stat distribution for a 510 bst onix is terrible.
160 SpA Poliwrath Scald vs. 252 HP / 252+ SpD Eviolite Onix: 204-240 (49.2 - 57.9%) -- 91.8% chance to 2HKO (both same bst of 510)
and given onix's lack of recovery i highly doubt it is "unkillable".
now lemme try a 510 bst rock snake:
HP: 95
ATK: 70
DEF: 135
SPA: 30 (same as og onix)
SPD: 110 (was 80 but i had 30 left over stats to put in)
SPE: 70
w/ eviolite this would be kinda hard to take down if you didn't bring a water/grass coverage move (which every team has).
also why give onix 65 spa?