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 navi 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 caalm 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.
He 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 Mrs. Mari.
Baryl dies in the past but uses the time tunnel to communicate with the Cross Fusion Team and Scilab. He does play a significantly larger role in the 45-minute movie Rockman.EXE: The Bequeathed Programs of Light and Darkness.
He has a parallel version in Beyondard.