Evasive Skills are evasive techniques that generally allow the user to evade attacks or defend themselves. However they are not always defensive or movement related as most allow the user to attack offensively as well as evade and/or defend. Unlike most techniques, Evasive Skills rely on stamina instead of ki in order to be used though some allow the use of ki with additional input to prolong their attack or effects.
As stamina is used for other abilities such as Boost Dash, Vanishing, or certain transformation/power-up skills such as Kaio-ken and its multipliers, Evasive Skills must be used more sparingly than Super or even some Ultimate Skills which rely on ki, unless the user has large stamina reserves, stamina restoring Capsules, and/or Super Skills (like Rise to Action, Charged Ki Wave, Super Drain, Hyper Drain, or Darkness Mixer). They also use up more stamina than other abilities as in Xenoverse 2, all Evasive Skills require 300 Stamina (or 3 Stamina bars) to perform thus can leave the user with low stamina if used to often or if their stamina reserves are low, which can leave the user unable to use their evasive skill when they need it most.
However Evasive Skills allow the user to interrupt various attacks, skills, and combos, while others have beneficial additional effects. They are also useful if the user is surrounded by enemies, or for putting some distance between the user and their opponent by either knocking the opponent back, by moving away from them, or attack while retreating or after evading. Some act as quick offensive attacks making them useful for counterattacking or surprising an opponent. Others are primarily defensive though most can still damage, push back, or debilitate the opponent in some way. Evasive Skills are generally not as powerful as Super or Ultimate Skills, and only a single Evasive Skill can be equipped to a user's skillset.