Phidia biology: Terrans, an umbrella term for Arknights' people, are "kemonomimi" or beast-like people, and Shalem is of the Phidia race, which references snakes-- he is most likely based on a Mexican black kingsnake. At first glance, he has pointed ears (implying excellent hearing), a prehensile tail with black scales, a forked tongue, slitted pupils, and sharp fangs. It's unknown if he has more snakelike traits, specifically from the snake he's based on, though it's likely. It's also mentioned that Terrans are naturally much stronger than Earth humans, and with much longer lives, especially if they have strong Arts.

Oripathy infection: A disease caused by exposure to raw Originium, an energy-emitting mineral, which currently has no cure or vaccine, only medicine to slow progress and alleviate symptoms. Contrary to popular belief, the chances of someone infecting others via proximity are quite low (but it is hereditary, and blood is infectious in specific circumstances). When they die, regardless of the cause, their bodies will crystallize and then disintegrate into Originium dust, which will become a new source of infection unless the corpse is incinerated. All infected will find Originium cells in their bodies, which will eventually multiply and interfere with internal functions-- very similar to cancer, except with crystal deposits. Some may even find crystals on their skin or mutations that affect their quality of life.

For now, Shalem has minimal deposits in his body-- specifically the circulatory system-- that appear as dark spots in scans and make his organs look blurry, but is confirmed to have neither crystals on his skin nor mutations. He wears a monitor given to him by Rhodes Island, standard equipment for all operators that tracks their infection rate and overall health.

Originium Arts & physical strength: Originium doesn't just cause Oripathy, but is also an actual source of energy that can be converted into something akin to electricity, and even magic, called Arts. Some are more proficient in Arts than others, though they all must use an item with some Originium inside to use it-- a processed stone is preferred to reduce the risk of getting infected. Those with Oripathy may suddenly be able to wield Arts, or do so without assistive tools, but using said tools is better to avoid aggravating their infection. Shalem's tool is a large shield, though he has powerful Arts, and is implied to have stronger proficiency in bladed weapons.

Shalem channels his power while employing defensive maneuvers, standing at chokepoints and blasting enemies that come close with Arts. Contrary to what his appearance suggests, he's a sturdy protector of teammates with stronger attacks but weaker constitutions, handling up to three enemies at once. If he's compared to the other defense-oriented operators, his defense is slightly weaker but his damage output is stronger, and he withstands Arts better. Because of his specialization, he's well-suited to countering those weak to Arts like heavily-armored troops, or stalling Arts-wielding enemies. It's implied, however, that he deliberately holds himself back from showing his true strength, and his preference for defense is an attempt at hiding or suppressing his true abilities.

He's also capable of seeing through some shadow-based stealth abilities due to having grown up around them. Thanks to his familiarity with old Crimson Troupe styles of fighting, he can counter some of them, but will have difficulty with the newer techniques.

Rapid Onslaught: Shalem gathers his strength and sends out fire-like Arts blasts faster, hitting all the enemies he's blocking. He can only keep this up for twenty-four seconds, but it can make all the difference.

Carnival of Self-Immolation: When a situation threatens to go bad, Shalem will drastically increase his Arts output in order to heavily damage every enemy within three meters before him for twenty seconds, sending bolts of magical electricity out of his body. As implied with the name, it's quite dangerous to him-- he doesn't receive any backlash or recoil, but the amount of Arts he sends out drains him so rapidly that he makes himself sick and weak, and Shalem will knock himself out if he doesn't have any source of magical healing, or magical stimulants on hand.

Proclamation of Doom: There's a slight chance for any enemy that Shalem hits to have their resistance to Arts/magic lessened, making them easy pickings for Arts users-- like himself.