What this app stores
Stored: the username you choose here and your Telegram user id, to know it is you. Your characters come from the legion's Telegram bot (the names you gave it). Nothing else: no email, no phone number, no password, no IP address.
Cookies: one technical cookie that keeps you logged in for 7 days. No tracking, no analytics, no third-party content.
Logs: requests are not recorded.
Delete: ask an officer, or leave the group: your access ends with your membership.