As can be seen here, Kangaskhan had access to Seismic Toss in previous generations. What would happen if Mega Kangaskhan used Seismic Toss?
Parental Bond
>Parental Bond allows the ability-bearer to attack twice. The second attack hits with half the power, so in effect Parental Bond is equivalent to a 50% boost to all attacks.
Seismic Toss
>The damage of Seismic Toss is equal to the user's level. So at level 100 the Pokémon will inflict 100 HP damage.
If Mega Kangaskhan with Parental Bond used Seismic Toss at Lv. 100, would the damage output be 100 + 100, or 100 + 50?