The BD tag indicates this is from the official Japanese Blu-ray release.
"The Girl's Truth" (or "The Empire's Assassin Blade" depending on the translation). Key Character: Lux Arcadia. Plot Focus: Lux confronts truths about the old empire and his past. [Witanime.com] SMNB EP 11 BD-HD.mp4
Character developments involving the main female cast (Lisesharte, Krulcifer, and Philuffy). Technical Breakdown The BD tag indicates this is from the
High-stakes Drag-Knight battles escalate as the season nears its finale. [Witanime.com] SMNB EP 11 BD-HD.mp4
The filename refers to the 11th episode of the anime Saijaku Muhai no Bahamut (also known as Undefeated Bahamut Chronicle ).