Unlike almost every other worthwhile mob, is highly susceptible to Requiem, which seems to have a dramatic effect on its regen. Requiem reduces its regen rate while in shell from 2% per tick, to 1% per tick.
When he goes into his shell, you can barely do any damage to him; however, continually doing damage will result in him coming back out of his shell (similar behavior seen in Aspidochelone).
When he goes into shell, he dispels all debuffs instantly, including Silence and Requiem. Silence and Requiem should be re-applied immediately after it goes into shell.
