This article will explain how to complete Elizabeth Request 75: Bring me a Sengoku-era helm in Persona 3 Reload. After defeating Full Moon Shadow, Elizabeth will give you a list of requests (optional). Completing these optional requests will provide you with rewards and cash.
The first head to the velvet room and accept the request from Elizabeth. Once you accept the request from Elizabeth then only you will be able to obtain a Sengoku-era helm for Elizabeth Request 75: Bring me a Sengoku-era helm.
Task: Bring a helm from the Sengoku era.
How to complete Elizabeth Elizabeth Request 75: Bring me a Sengoku-era helm
After accepting the request, head to the Gekkoukan High School. In the school enter into the Faculty Office located at the F1 level.
In the Faculty Office, speak with NPC (Mr. Ono). You have to come every day after school until the NPC (Mr. Ono) rewards you with a helm from the Sengoku Era.
After collecting the Sengoku Era, head back to Elizabeth and give her the Sengoku Era to end request number 75.