The Sentinel

Marcus Cotton is The Sentinel (formerly "Sir Jedi Sentinel"), "watching over geekdom." He has been making Doctor Who videos since September 2017. While he has talked about several subjects, the main focus of his channel is Doctor Who. He has two separate series in which he discusses Who-related content:

Sentinel Vlogs: His more casual series. Here, he talks about general topics in regards to Doctor Who, such as how he got into the show, his favorite companions, his ranking of the Doctors, and his rankings of the Masters. In Sentinel Vlogs, Cotton also does unboxing videos, reviewing the Who-related merchandise he's acquired.

Sentinel Reviews: Here, Cotton takes an amateur look at various Who stories and reviews them. The bulk of his content in this series is Big Finish related, including reviewing every release of the spinoff The Diary of River Song as well as series 8 of The Fourth Doctor Adventures. He has also reviewed series 11 and 12.

Cotton regularly points out that he's unscripted and very scatter-brained, which leads to frequent pauses and rambling.