Zack Kassian is best known these days as the chief protagonist for the Edmonton Oilers in their latest on-ice war with the Calgary Flames.Fresh off a two-game suspension for pummelling Calgary forward Matthew Tkachuk, all eyes are on No. 44 for Edmonton in the renewed Battle of Alberta. Kassian and the Oilers tangle with the Flames Wednesday at Rogers Place in Edmonton and then again Saturday at the Scotiabank Saddledome in Calgary.NHL director of player safety George Parros has warned both sides to behave.In the bigger picture, however, Kassian is the author of a different kind of story — one of capitalizing on last chances and moving on from past mistakes."There's a calmness to my life now where it used to be very rocky," said Kassian, who turned 29 this past Friday. "Now, I'm at peace with a lot of things away from the rink which I think, in general, helps me a lot on the ice."Patrolling right wing on the first line with Connor McDavid and James Neal, Kassian is on-pace for a career season with 13 goals and 28 points in 44 games.The Windsor, Ont. native is expected to sign a contract extension with the Oilers before the NHL's trade deadline on Feb. 24. "It's been a good year so far," the six-foot-three, 211-pounder said with a gap-toothed grin. "I feel like I've proven I can play anywhere in the lineup, which is a good asset to have."Back in 2015, Kassian appeared to be on the verge of falling out of the NHL all together due to carnage in his personal life. Employed by his third NHL team at age 24, Kassian was set to play his first game with the Montreal Canadiens. Three days before the season opener, he broke his nose and left foot when his vehicle hit a tree at 6:30 a.m.Police charged a 20-year-old woman with impaired driving. Kassian admitted to being heavily intoxicated in the passenger seat after a night of partying.Suspended by the Canadiens — and ultimately traded to Edmonton for goalie Ben Scriven — Kassian entered a treatment centre in Southern California.He exited with a determination to take things a day at a time and resurrect his hockey career."For me, I think now that I'm a fun person," said Kassian, a first-round (13th overall) selection of the Buffalo Sabres in the 2009 NHL entry draft. "I even joke around about my past a little bit — about how I came through adversity and a lot of the dumb stuff I did."That stuff, I really had to clean up."These days, Kassian is much beloved in the Oilers locker-room. His teammates roared to the big man's defence after his double minor for ragdolling Tkachuk on Jan. 11 arguably cost Edmonton two points. Elias Lindholm potted the game-winner with the man advantage and Calgary won 4-3."He's our heart and soul in this group here," star centre Leon Draisaitl told reporters when the Oilers arrived back in Edmonton. "Everyone loves him."Everyone on this team really admires what he does on a nightly basis."Defenceman Darnell Nurse echoed those sentiments."He's a heart and soul guy," Nurse said. "He's a guy that brings a lot of life to this room. He's important not only on the ice, but off the ice with the energy he brings. And he's a guy who always plays between the lines, too. He's a hard player, not a dirty player."He's a guy who plays hard for the guys next to him. We're very fortunate to have him."While media types have branded Wednesday's game as Kassian's chance to exact revenge, the man himself understands what's at stake."Look at our division," he said before the all-star break. "Look at the Pacific and how tight it is."Indeed. The Vancouver Canucks reside atop the Pacific Division with 58 points. The Oilers, Flames, Arizona Coyotes and Las Vegas Golden Knights are all one point back with 57.All five teams have sat in first place at some point this season."You have a bad week of hockey and you're out of the playoffs," Kassian said. "We want to capitalize and get as many points as possible."