The hulking defensive tackle helped the Lions win the 2011 Grey Cup, however a series of incidents on an off the field the following season precipitated a trade to the Toronto Argonauts prior to the 2013 campaign.
The mercurial Mitchell rebounded in Toronto and asked for his release from the Argos to pursue NFL opportunities this winter, but when those failed to materialized the Lions surprised the rest of the CFL by bringing him back into the fold.
"I think he's a person that's matured. He's a person that's experienced some things," Benevides said at training camp this week. "The biggest thing I see is everybody else understanding who he is.
"I think he's very conscious of what's occurring and what's going on around him. What people need to know is he is not a bad person. He's a good person."
Benevides would know.
He was the Lions' defensive co-ordinator back in 2011 when Mitchell had his best season, compiling 33 tackles and six sacks.
"I see everybody understanding who he is and sometimes you have a misconception or you don't understand someone and that sometimes creates issues," said Benevides. "Khalif is a very charismatic guy, he's a very passionate guy. He enjoys the game. His teammates and his team and the guys around him are very important to him."
But it was those teammates who wanted him out the door after the six-foot-six, 315-pound Mitchell made headlines for all the wrong reasons in 2012.
The league suspended him two games for violently hyperextending the arm of an opponent that July before fining him an unspecified amount for making multiple throat-slashing gestures in another game. Mitchell was then fined and suspended again for violating the CFL's social media policy after using a racial slur on Twitter.
Benevides said the team's leadership group was consulted when the idea to was first floated to bring Mitchell back, and it was agreed that all parties could move on and work towards winning the Grey Cup, which the Lions host in November.
"It was a long process and discussion. There was a lot of guys that I spoke to and they were the ones who said 'Bring him back in the room,'" said Benevides. "At the end of the day we all have a job to do and that's win."
But while his coach has seen growth and maturity, the 29-year-old Mitchell emphasized he's still the same person in many ways.
"I haven't changed who I am. Even when I came back to B.C. I was like 'I'm going to be Khalif' and they were like 'We understand that,'" said Mitchell, referring to himself in the third person. "I think a lot of people don't understand who Khalif is because a lot of people only see me in football or from the negative things that I've produced in the media."
Lions running back Andrew Harris expressed delight when Mitchell was traded last year, tweeting "Good riddance!!!!" after the deal with the Argos was announced.
The Winnipeg native said he's willing to move on because of Mitchell's unique skill set and a hope that he has learned from his mistakes.
"Khalif is a beast. He's a guy that can help us win football games, and that's the most important things," said Harris. "All the off-field stuff that happened in the past, it's just maturing from that now. Things happen with people and you've just got to move on from that and trust that there will be better judgement in the future.
"There's definitely no animosity between us. We're teammates now and we're just working together for the one goal and that's the Grey Cup."
Lions linebacker Solomon Elimimian added that there weren't any awkward conversations when Mitchell walked back into the locker-room.
"I think the guys all know Khalif, and that's the biggest thing for us," said Elimimian. "We know that he's a good guy. We know he means well. We know that he's a very bright man. But also the thing is he's a great football player and that's what we need in the locker-room and on the field."
Lions defensive back Ryan Phillips said it was made clear to Mitchell upon his return that he can be himself as long as it doesn't hurt the team.
"Just understand that there's consequences to mistakes," said Phillips. "He's grown up from that. We know the dominant player he can be as long as he's focused on football."
There's no doubt that Mitchell will help an already solid defence get better. The Lions surrendered the second fewest rushing yards per game (94.4) in 2013, but allowed the second most rushing touchdowns (17) and recorded the third fewest sacks (45).
Mitchell put the drama from 2012 behind him and nearly matched his 2011 numbers while playing with Toronto last season, registering 32 tackles and five sacks.
"In order to be successful in our division, you've got to be very good against the run. You've got to be big inside," said Benevides. "He's another big, effective body that can have an impact in the interior line of scrimmage, and good teams win at the line of scrimmage."
Mitchell said he never expected to return to the West Coast after his messy divorce with the Lions last year, but is ready to do what he does best — stop the run and get after the quarterback.
"I definitely wasn't expecting to come back. I'm sure when they told me 'Good riddance' and 'Bye' they weren't expecting me to come back either," he said. "I'm here now and regardless of what the situation was, at the end of the day we've got to win a championship."