Twilight of Valhalla

Painting Magic: Twilight of Valhalla (絵画魔法『黄昏のヴァルハラ』) is a Painting Magic spell.

Description
With an open grimoire, the user manifests a paint brush and a palette and, with a swipe of the brush, creates a multistory building and winged, female warriors to defend the user and anyone else in the building. The roof is decorated with shields of various shapes and designs, and the warriors are armored and carry shields and lances.

After a short time, the spell's secondary effects kick in: increasing the magic power of those within the building and preventing them from dying despite any injuries. Due to this delay, however, the user could be killed before the effects activate. Additionally, attacks from those inside pass through the spell's boundaries, allowing them to combine attacks with the spell's valkyries.

Trivia

 * In Norse mythology, Valhalla is a large hall covered in golden shields and is where valkyries lead the souls of dead warriors.