Pancreas, a Diabetes Bag

Fixing Lows — If you would lose life on your
turn you may instead return target permanent
card from your graveyard with mana value equal
to or less than the life that would be lost to the
battlefield under your control.
Insulin Dosage — If you would gain life on your
turn you may instead have target creature -0/-X
until end of turn where X is the life that would
be gained.
Partner
This artifact can be your commander