To get access to your Battle Legion account on all of your devices, you need to link the account to either your Apple ID, Facebook or Google account.
This can be done by tapping on Settings, and tapping the 'Disconnected' status under the Apple ID, Facebook or Google account.
After your Battle Legion account is linked, simply make sure you have added the linked Apple ID, Facebook or Google account added to your new device. After this, simply tap on 'Disconnected' status for the Apple ID, Facebook or Google account in the Settings menu.
Warning! Be careful when linking your Battle Legion account to Facebook as only one Battle Legion account can be linked to your Facebook account. Linking a new Battle Legion account to your Facebook account will cause the previous Battle Legion account link to be discarded.
This means that you can no longer use Facebook to connect to that Battle Legion account. If this Battle Legion account is not linked to Google or iCloud, overwriting the link will cause the account to become unrecoverable.
When using the 'Delete account' feature, Facebook links will not be severed. This has to be manually done by the player.