252+ Atk Parental Bond Mega Kangaskhan Return vs. 252 HP / 252+ Def Eviolite Porygon2: 139-163 (37.1 - 43.5%) -- guaranteed 3HKO
(139, 139, 141, 144, 144, 145, 148, 150, 150, 153, 154, 157, 157, 159, 162, 163)
252+ Atk Parental Bond Mega Kangaskhan Power-Up Punch vs. 252 HP / 252+ Def Eviolite Porygon2: 75-90 (20 - 24%) -- guaranteed 5HKO
(75, 75, 78, 78, 78, 81, 81, 81, 81, 84, 84, 84, 87, 87, 87, 90)
+2 252+ Atk Parental Bond Mega Kangaskhan Return vs. 252 HP / 252+ Def Eviolite Porygon2: 274-324 (73.2 - 86.6%) -- guaranteed 2HKO
(274, 276, 280, 283, 288, 289, 294, 297, 298, 303, 306, 310, 312, 316, 319, 324)
Pretty badly imo, considering it gets maimed by +2 Return even when going full defensive (in which case you lack the offensive presence to really do anything other than toxic)