Drevet's Final Gambit

Upon casting this spell you have gathered all possible life energy within you as a final burst. Each target in a 25 foot radius must make a constitution saving throw. On a failed save the target will take the full damage of this spell, half on success. The caster will reduce their HP to 0 and multiply the result by 5d8. The caster is turned to stone ans is considered dead. Cannot be revived except by a 9th level wish spell.