Okay, this fact is long and complicated, so read it at least twice:

The symbol on the back of Lloyd's ZX suit means Ouroboros (like the lost Serpentine city) and means something that is eternal or never ending. It is sometimes called 'snake biting it's tail'. It shows something that cannot be extinguished or stopped. This fits perfectly for Lloyd since he's the Ultimate Spinjitzu Master, after the first one, and FSM never actually gave up, just let the fight between good an evil continue.