[Updated June 4 6:00 PM] If you claim it from the gift-box notifier, be sure to use it before it expires.
There is currently an issue where characters that use the Mega Character Burninator will lose the effect when they log out of the game. This is not intended, and we plan to fix this issue during our next scheduled maintenance. Those that have used the Mega Character Burninator will have the character's burning time extended once the issue is fixed. We apologize for any inconvenience, and thank you for your patience.