4 cards where the illustration contains “imperial-symbol”

Heiko Yamazaki, the General (Kamigawa: Neon Dynasty #321)
Imperial Oath (Kamigawa: Neon Dynasty #17)
Ironsoul Enforcer (Neon Dynasty Commander #7)
Norika Yamazaki, the Poet (Kamigawa: Neon Dynasty #311)

This search is finished. Now the real work can begin.