Three new cast members have joined Star Trek: Discovery bringing the total known casting to six. The three will be playing Klingons in the series which suggests the series will use them as the main bad guys since the series is set why the Federation is still at war with them. Chris Obi (American Gods) will play T'Kuvma "the Klingon leader seeking to unite the Klingon houses". Shazad Latif (Penny Dreadful) will be Kol, T'Kuvma's protege and a commanding officer. Mary Chieffo (Miss Dial) will be L'Rell who is a "battle deck commander" on a Klingon ship. What ship the Klingons will be flying on in confrontations against the Discovery crew was not named.
The character phrasings are a bit bizarre and likely written by a PR flack that knows nothing of Star Trek but it basically reads as Klingon Captain, Klingon second officer and bridge specialist. Being Klingons, they have political desires that extend beyond their ship and reaching those desire typically means waging successful campaigns against enemies of the Empire.