Toyotomi's spell that doubles a completed fortification's structural strength.
Toyotomi plans to cast Edifice Shield on The Nest once the final block is placed and the master-quality completion bonus raises the tower from 150% to 200% strength. The spell doubles that figure again, giving the synergy tower a structural rating no siege on the battlefield is expected to crack.
Combined with the lattice of per-block protections, Princess Donut's Sentry and Flak spells, and four Deflector Towers, Toyotomi claims the result will be safer than The FUPA itself, and buoyant enough to float if the ground beneath it disappeared.
The capstone protective spell on the Nest tower.