This means that you can use your reach weapon (the whip) to perform the action (except you technically can't grapple, because the rules state you must use at least one free hand; we'll get to that in a second). When grappling, you can already move the grappled creature. All ...
As far as I can tell, the real question is whether "spell using the weapon as a spellcasting focus" counts for the "with that weapon" requirement of the Reach property, but I haven't been able to find a clear answer on that. dnd-5e-2014 feats warlock opportuni...
Water weirds (MM, p. 299) have the Water Bound trait: The water weird dies if it leaves the water to which it is bound or if that water is destroyed. If a water weird is fewer than 10 feet from the edge of its pool—which it would be if it were trying to ...