Spell - Elemental
Requirements: 9 Combined Tiers of Athletics and Observe
Target creature in 3 + TT range gains Burrow as a Secondary Movement type. With each space moved, they can pay 1 Movement to leave a tunnel 2 sizes smaller than them in that space. After each minute, the tunnel rolls 2d12. If two or more are face value 1, the tunnel collapses.

1 + TT minutes

Magic
Boost: They can leave a tunnel without expending Movement. If they do, the tunnel rolls an additional 1d12.