PSA: 252+ SpA Life Orb Lapras Thunder vs. 252 HP / 252+ SpD Milotic: 86-101 (42.5 - 50%) -- 0.4% chance to 2HKO
Milo has Mirror Coat to retaliate, as well as Hypnosis for disruption. Pretty sure the only thing that can OHKO it from the special side without boosting in this format is Specs...