Itsuka Kendo and Tetsutetsu Tetsutetsu team up to find and defeat the villain Mustard, who is filling the forest with a lethal, sleep-inducing gas.
A Matroska multimedia container format commonly used for high-definition video files. BnHA_S3_05_Pro_AB.mkv
This likely refers to the release group (or encoders) or specific audio/subtitle tracks (such as "Audio Japanese/English" or a dual-audio release). Itsuka Kendo and Tetsutetsu Tetsutetsu team up to
The League of Villains' Vanguard Action Squad launches their assault on the training camp. BnHA_S3_05_Pro_AB.mkv
Mandalay broadcasts a telepathic message warning the students that they are under attack by the League of Villains and gives permission to fight back.