The guy who actually writes up the rules has,already stated quite clearly that it will be the official ruling, and that the next version of all weapon Trance spells will be a trance, copying (almost verbatim - just change the weapons) the Arrow Trance from Bestiary:
Arrow Trance
1 Point
Self, Temporal, Nonstackable
This allows the user to merge their consciousness with their bow, doubling their bow skill rating. The user enters a trance in which the only things that exist are bow and targets. The user moves only to get a clear shot or find another target. The user can use no other weapon and cannot parry nor use the bow as a club. Even if engaged in melee, the user will fire an arrow at their opponent. While entranced, the user may cast only bow-related magic (Multimissile, Speedart, etc.) to the exclusion of all other magic, including healing (except that the user can heal their elf bow if it is damaged). If the battle ends before the spell expires, the user will stand at rest and wait for new targets. This is not a Berserker spell; the user knows who their friends and enemies are.
So, Earth Shield is of no use here (until you Heroquest and get a pass on that).
Alternatively, get a Shield Trance spell, or Earth Sword/Axe spell