The Invulnerability sphere is a returning powerup that appears in Doom (2016). It is green in color.
UAC REPORT FILE: 98THE72Z
When it is absorbed, this stimulant diffuses Argent plasma to the basal layer below the dermis creating a tough film of bioplasma beneath the skin that protects the user from external attacks. This can make the demon almost entirely invulnerable until the plasma has been dissipated through repeated punishment. The bioplasma comes into direct contact with the nerve cells beneath the skin which causes excruciating pain throughout the process. This increases the likelihood that, in the throes of agonizing torment, the mindless demon will try to attack targets that are clearly beyond their ability.
When the player picks up a Invulnerability powerup, the edges of the screen gain a green tinge. The effect lasts for approximately ten seconds.