Baryl was adopted by Wily at an early age when his father went off to war. Wily created Colonel.EXE for Baryl. Colonel was the perfect NetNavi because of his tactical prowess, and his weapons destruction program. One day, Wily took Colonel away from Baryl and removed his kindness and weapons destruction programs, using them to create Iris.EXE. This was the day Baryl's father died. Baryl says that Colonel was never the same after this. Wily stated that this event was the point where he threw away his own kindness.
Baryl becomes a karate master and defeats Joe Mach in a competition but befriends him and teaches him.
After Nebula's revival in MegaMan Battle Network 5. Baryl and Colonel test Lan and MegaMan.EXE to see if they can join Team Colonel which they pass. Baryl displays a tough attitude throughout the game and is a capable leader. He doesn't stand for weakness though like when Lan refused to act after MegaMan was captured. He remains calm and controlled even when Colonel was supposedly deleted. After discovering Nebula's base, he leads them on an attack to end their threat. After Nebula Grey is deleted, Dr. Regal recognizes him (probably because they've met before since he is Dr. Wily's son and Baryl is Wily's stepson) and states that he is Supreme Commander of Netopia's Network Corps. He evacuates initially but comes back and helps Dr. Wily rescue Dr. Regal from the volcano. He disbands Team Colonel later. When Lan asks who he is, he says that he is no one special, just Baryl.
In the Team ProtoMan version of the game, Baryl only appears twice, the first time sending in Colonel to help save ProtoMan.EXE from the Dark Soul and the second being after the deletion of Nebula Grey.
Baryl and Colonel have joined the WWW and commands the other members, even though he joined late. He is harsh and strict, which creates discontent among the other members. Baryl and Colonel fight and lose to MegaMan and Lan in the Underground. Lan talks to him and Baryl has doubts about what he is doing. Yuika, Vic, Blackbeard and Ito get mad that Baryl is bossing them around so they split from the WWW. After Blackbeard is arrested, they kidnap Iris and use her to lure out Baryl. Ito and Vic beat up Baryl and are about to kill him when Joe Mach arrives and fends them off. Baryl appears again in the final battle against the Cybeasts and sends Colonel to fight them but collpases because he is badly injured. When Falzar and Gregar are defeated, he stays behind in the exploding room. However, at the end, Ms. Mari gives Lan a CopyBot, saying it was from a man with Baryl's features. In the credits, he is seen walking past Ms. Mari.
Baryl's role in the anime is more complex. By the time the events on Stream begin, Baryl is already on his fifties and paralytic. He dies shortly after the begining of Stream, but not before he convinced Lord Wily to abandon his schemes of taking over the Network and requesting him to build a machine called the 'Time Server' to allow for Navis to time-travel.
After Duo's Comet crash-lands on Earth, it opens up a space-time tunnel named 'Past Tunnel' that leads to the world of 30 years before. It is then that is revealed that Colonel in fact comes from the past of 20 years ago and is using the 'Time Server' to travel to present time. Being one of the Chosen Ones of Duo, Baryl fights against the Asteroids and Slur as well. He does play a significantly larger role in the 45-minute movie Rockman EXE: Program of Light and Dark. He uses the space-time distortions originated from the activation of Spectrum caused by Dr. Regal to physically travel to the present time and help out Lan defeat Nebula Grey. He then returns to his time and uses the 'Time Server' to communicate with the present.
When it's made clear that Duo is set on erasing Earth, Baryl uses the Spectrum project to transform himself into data and travel again to the present using the 'Past Tunnel' created by Duo. In the end, he becomes a test subject for Duo to study so that he can try to understand why NetNavis and humans work together and how is it that they can use Cross Fusion. He mades one final communication before departing with Duo and Colonel.
Baryl and Colonel have a parallel version in Beyondard that helps Lan fight against the Zoanoroids. He is firstly seen in Episode 14 saving Lan from a virus stampede. He returns some episodes later, in Episode 20, having failed a mission to try to infiltrate Gregar's main base and try out a new weapon against it. Colonel was infected by the 'Beast Factor' as a result and become a Zoanoroid, although he is later temporarily restored by the combined efforts of Iris and Trill. He bids farewell to the people from Earth once the 'Beast Factor' of Beyondard has been wiped out.