Open skills vs Grims

[GonFreeces31]

So I feel like such a noob asking, but I've gotten to level 50 and still can't figure this out...

What comes first, open skills or grims? I was playing a merc nation file today and couldn't figure out if it would be better to use horseman or miracle fruit to avoid a return.

[DWildstar]

Grims always go first. Which grim goes first is random.

[Artist]

And then open skill activates depending on their agi, which is why emerald carbuncle is always anti-shade, and so is strike sorc.

[Phenoca]

Grats on Lvl 50 : )
Which is why tofu owned AngelicDeath's Level 3 with a Return grimoire before Folrart Lady Paladin could give it Lvl +1.
@Artist: My thoughts exactly.