Smaller. If saving with Artifice, target gains an Advantage for each size smaller they are than you.
Bigger. If saving with Might, target gains an Advantage for each size bigger they are than you.
While grappling the target:
If the target of your grapple moves, you can use a Free Reaction to use Movement from your next Turn to move with them, preventing the end of the grapple. (If you Mounted the target, you force the target to carry you instead.)
You are Blunted against all but the grapple target.
Breaking free from a Grapple
As an Action, the target can attempt to break free from your Grapple. When they do, you will first perform your choice of a Might or ArtificeTest using the same Penalties above. The target must then Save using the same Stat that you chose.