The name 'Mystysha' is an ancient Slavic bi-base personal name that arose from the truncation of the full name example Mstislav and the addition of the suffix -sha. This name is first mentioned in 944 in chronicler records: "the voevoda was Svyeneld, also the father of Mystishin" (PSRL I 55). In 1469, among the Cossacks of the Bratslav regiment, there is a reference to a person named Malyk Mystkovskyi, whose name base resembles that of Mystysha (RVZ 253).As for the variant of the name 'Mytus', according to L. Makhnovets, Mytus is a calendar name for Dmytro (LR 494). The anthroponym Mytus contains the name of a famous singer-warrior from 1241 named Mytus from Peremyshl (Krypiak GV K 158; IL 528). This name variant is also mentioned in 1495: "the serf Andriiko Mytus" (Tup 252).