This was discussed as a possible development path for Shef, so figured it's worth dumping it here. It's also something the Unflappable Shinobi dipped into.
Surgeon's Eyes
Regalia-like eyes first expressed by a clan of eye surgeons. Enhances perception and magic detection. Manifests as red eyes when active with a thin ring around the pupil and tomoe symbols resting on the ring. At Level 1 there is one tomoe, at Level 2 two, at Level 3 three. At higher levels one's hands and magic becomes steadier and one's bedside manner improves allowing more unruly patients to be wrangled with greater efficiency.
Surgeon's Eyes, Veil Piercer Mode
Eyes that have perceived death. An additional mode for the Surgeon's Eyes that is only unlocked by witnessing death and loss, traditionally understood to be the loss of one's patient. Veil Piercer Mode catches a glimpse beyond death into the depths of Akasha and draws power from within it granting a single new ability, often of esoteric properties. This mode is rather taxing to use however and is thus normally kept reserved for emergency situations. Surgeon's Eyes instantly advances to Level 3 if has not reached that state already. Additionally, the user becomes capable of manifesting an aura-based exoskeleton to assist in their duties. In this mode, the eye design changes to have a pattern with rotational symmetry around the pupils.
Surgeon's Eyes, Perfected Veil Piercer Mode
Sight that surpasses sight itself. It can only be obtained by performing a full eye transplant on one's self completely unassisted. For most of Godslayers, this would mean a double eye transplant in a single operation. This completely decouples Surgeon's Eyes from one's own eyes, allowing it to be used through other visual-like sensing mechanisms including optic sensors and the like and reduces the drain of keeping Veil Piercer active to negligible levels. The Veil Piercer pattern typically mutates at this stage.