Personally i dont like gaming channels but i think i might be able to give you some feedback.
*Your thumbnails progressed in a good way as you posted more videos
*your videos are EXTREMELY long try to shorten them up and only put only the highlights of your gameplay in or when your not doing anything fast forward that so you can get to the good gameplay faster
*Gonna say it again, but i think your newer thumbnails are pretty good
*Great intro to your video, but kind of generic (with the dubstep as a backround song)
*Great outro
*one thing that really annoyed me was the same dubstep song constantly playing in the backround throughout your entire video.
*make that DOTZ watermark smaller, i felt like it was covering like your entire video.
*try and branch out and play different games, there are tons upon tons of people who play black ops 3 and to me your channel is just another black ops/ call of duty channel, but if you want to stick to black ops, by all means, go ahead.
overall id give your channel a strong 5/7 because its well organized, just shorten your videos up and, try and branch out to different games.