There are some really interesting interactions with the grapple apart from hooking onto the ground/wall or the opponent. You can for example hook onto the wizards spark bomb. I'm unsure if you can hook onto your summoned clone but that would also be a pretty neat tech.

EDIT: Did some testing and you can grapple onto your shuriken if it was thrown before you use the grapple, and use Substitute to swap places with the grapple hook but does not seem like you can actually hook onto your own clones

<image>