As simple as the title i think we should be able to donate spells just as we are able to donate troops. Also a good spell idea would be a rain storm spell which rusts weapons like cannons and mortars to the point were they fall apart and rots wood in things like archer towers and the lightning would destroy wizard towers. This spell would take up the space of 5 normal spells and would be able to take out any defense no matter the level. Oh and last idea would be to have the ability to use spells donated to you for defense across the map everywhere.

