Do terramotes increase or decrease crit damage?

Primal Landslide reads:

When you Immobilize or Stun an enemy, you gain a Terra mote. Each enemy hit by Landslide consumes a Terramote causing a guaranteed Critical Strike with 40% [x] Critical Strike Damage. Bosses always have up to a 10% chance to grant a Terra mote when hit.

The way that’s phrased has always bothered me, so my question is this: Does this provide a guaranteed crit at only 40% crit damage, or does it provide a guaranteed crit with +40% bonus crit damage?

I haven’t used Landslide but when I read the skill it sounded like it was 40x bonus damage. The other way would make it pretty bad IMO.

It’s a damage buff and guaranteed crit

It is a guaranteed crit with x40% extra total multiplier. Very powerful.