add earth 4

spells/Earth4.tex

+\spell{Snowcastle}% Name
+  {\mEarth}% Spheres
+  {Wax}% Action
+  {\detailed, \distant, \duplicated}% Enhancements
+  {weather conditions}% Resist with
+  {during a snowstorm, the caster guides every snowflake to settle into a great ice-castle}% Description
+  {
+    The caster cries to every snowflake in a snowstorm, to settle and bind into ice.
+    Brick by brick, they form a castle of ice, \spellArea\ wide and long.
+
+    The castle only has shape, no doors, shutters, or anything more than halls and rooms.
+    However, those halls always come covered in symbols, writing, or other elements from the caster's subconscious.
+    The caster can give the dwelling any property they can realise within the limitations, and the spell's total potency enforces those ideas.
+    A maze-like castle will add +\arabic{spelllevel} to the \gls{tn} to navigate it, while an impregnable castle will add a penalty to assault it.
+  }
+