This instructional video features Seiyunchin kata in regards to application principles, renzoku (continuous) bunkai, bunkai drills and connector drills and thoughts on kata in general.
Please note that this is NOT the video of the recent Seiyunchin Renzoku Workshop. That is available here: https://gkcglobalshop.com/products/seiyunchin-renzoku-bunkai-workshop
However, this video details the connector drills that assist the renzoku drills, in addition to a number of interesting and advanced variations that are a must.