Time field absorption

A circular field is created, which is 40 x 40 ft. and 20 ft. tall, as they choose the place to place it at. Anyone caught in the field must make a constitution saving throw of 15. On a fail, their life span is drained as they receive 2d8 damage. The hit points absorbed are than transferred to the caster. If the caster is already at full health, the additional hit points then become bonus hit points. The person also has the option to share it among their allies if they are close by 10 ft.. On a save they receive half the damage. The same thing will repeat if the people in it stay in there until their next turn. However the caster can choose up to five people to not be affected by the field.