Is damage associated with Powerful Charge instead of or in addition to standard attack?

[equestech]

The special attack Powerful Charge indicates that it deals extra damage in addition to the normal benefits and hazards of a charge. But it is unclear if this is in addition to the melee attack you would normally get at the end of a charge or instead of it.

For example, Arsinoitherium lists powerful charge (4d8+13). And also has a melee attack of gore +14 (4d8+13). So is the damage from the powerful charge in addition to the gore damage or instead of the gore damage?

[Darksol the Painbringer]

Yes, it's increased. Re-reading the Universal Monster Rule, it says:

Powerful Charge wrote:

When a creature with this special attack makes a charge, its attack deals extra damage in addition to the normal benefits and hazards of a charge. The attack and amount of damage from the attack is given in the creature’s description.

So, whenever the creature would hit with a powerful charge, it would take the base damage (the gore), and then add the powerful charge damage on top of it.

For this creature, its powerful charge would deal a total of 8D6+26.