Indrik will be avaiable for completing tokens from 3 different events, starting with Midyear mayhem.
"The first event to feature Event Tickets will be the Witches Festival, which is being turned on during this PTS patch."
"This unique, account-bound Legendary Feather is a Runebox Fragment; the remaining three Runebox Fragments will become available during future events."
"While we won't spoil what they combine into just yet, be aware that the thing they create when combined will also be account-bound and untradeable."
https://forums.elderscrollsonline.com/en/discussion/425575/pts-patch-notes-v4-1-1/p1
So four fragments redeemed with Event Tickets, starting with Witches. With no official confirmation, it could be an Indrik but all guesses are speculation until somebody actually assembles them.
So please stop stating speculation as fact, especially when the actual facts are also incorrect.