Shiro has several prosthetics.
Getting his brother free from unknown tech literally grafted onto him was kinda at the top of Ryouâs To Do listâmade worse by the Galra continuously finding them and Hunk being of the same mind, too. Ulaz literally storing data like his brotherâs a Flash Drive was the last straw. (Shiro fought Ryou on getting it removed Immediately after Alluraâs captureââmore pressing mattersâ with Pidge chiming in that she can just hack around it.) MAYBE itâs Just the Black Lion. But Ryouâs done taking any chances (and the Lion having a tyrant in her circuitry doesnât explain everything.)
So...Shiro ends up with a new arm, and then some. All detatchable, some weaponized, some not and simply designed for Everyday Comfort and Durability. At least one arm is basically a glorified swiss army knife, which gets heavy use from Shiro. Ryouâs constantly fiddling with the remains of Shiroâs Galran Tech removed to try and figure out how the darn thing admittedly functioned with such a high degree of response. (Ryou also discovers other secrets that cause him to wake up screaming. Shiro always demands to know whatâs wrong, but all Ryou can do is hold his twin tightlyâTakaâs better off not knowing if Ryou can help it.)
Besides constantly tinkering with Shiroâs prosthetics and the old one, and always looking ways to improve his designs, Ryou also makes Shiro arms that are simply for Just Fun. (well, so long as the fingers and wrist and elbow respond. Style doesnât entirely substite substance.) Arms with hands that float freely. Arms that are transparent. Arms that glow an ever changing gradiant of colors. Ryouâs pride and joy is an arm that glows and shimmers with starlight and can even display charts both on the forearm and project from the palm and fingers.
However, none of Ryouâs designs can hold a candle to the Black Bayard in comfort, function, versatility, and power...which heâs completely okay with. (Shiro does insist on using Ryouâs Designs fairly frequently, especially after he learns to make other forms with the bayard. But on days when his remaining flesh is simply too tender for anything to touch for long periods, Blackâs Bayard is Shiroâs preference. Especially if thereâs a chance on getting called on a mission.)
When the BlackLion drags Jiro home and demands to keep him, heâs absolutely overwealmed by the sheer variety Ryouâs made for Shiro, and touched that Shiroâs insisting that Jiro can share with him until Ryou can make something a little bit more specific for Jiroâs wants and needs.
This timestream may be different in ways Jiro couldnât anticipate, but this time Jiro isnât stuck waiting for an arm that isnât designed to hurt him or wondering if heâs accepted.
(He does want his own StarChartSpacArm. Takaâs not sharing that one.)