Spell: Earthbreaker Stride

The ground parts for you as you move. You gain a burrow Speed equal to your land Speed; you can burrow through solid stone and structures made entirely of rock or stone, though you treat such substances as difficult terrain. When you Burrow, you leave behind a stable tunnel that's 5 feet wide and 10 feet tall. You can't Burrow further than 100 feet from the nearest surface.

You can Dismiss the spell at any point to collapse the tunnel, which pushes anyone within out through the nearest exit. If the tunnel remains at the end of the spell's duration, it remains as an ordinary, non-magical tunnel.