It will be put into its owner’s graveyard as soon as one of its abilities resolves that puts its toughness at zero (or less than the current amount of damage on it). This is a state-based action, so there is no way to activate its ability any more to increase its power further before it is put into the graveyard.
Legalitet:
Standard: Ej legal
Pioneer: Ej legal
Modern: Ej legal
Legacy: Legal
Vintage: Legal
EDH / Commander: Legal
Pauper: Ej legal
Explorer: Ej legal
Historic: Ej legal
Brawl: Ej legal
Premodern: Legal
93/94: Ej legal
Flowstone Hellion är Legal i dessa block: Rath Cycle