Williams was born in North Easton, Massachusetts and attended Catholic Memorial School. While at Catholic Memorial, Williams was a member of PrepStars High School All-America team, a member of the "Super 26" team in 2008, an all-scholastic by the Boston Globe and Boston Herald. He was named all-conference as both a junior and senior. He was rated as the eight best offensive lineman in the country by SuperPrep All-America. Rivals.com rated him the seventh best offensive guard in the country. Scout.com rated him as the 15th best offensive lineman in the country. ESPN.com rated him the 35th best offensive tackle in the country. He was also a member of the Rivals 250. He also played in the U.S. Army All-American Bowl. On February 15, 2014, Williams's number 73 was retired by Catholic Memorial.
The Houston Texans selected Williams in the third round with the 89th overall pick of the 2013 NFL Draft. He would go on to miss his rookie season with a microfracture in his knee. On July 21, 2014, he was released.
On February 20, 2015, Williams was signed by the Jacksonville Jaguars, to a two-year contract, with the intention of being a back up to starter Jeremy Parnell. On August 29, 2015, Williams was released by Jacksonville.
After being released by the Patriots, Williams returned to Houston to train to become a professional wrestler. On October 27, 2015, it was announced that Williams was being trained by WWE star Booker T to become a professional wrestler. He made his debut with Reality of Wrestling on February 1, 2016, under the ring name of Marcellus Black.
WWE
NXT (2016–present)
On February 11, 2016, Williams participated in a WWE try-out at the WWE Performance Center in Orlando, Florida. On August 1, 2016, WWE officially announced the signing of Williams, who started training at the Performance Center the same day. He made his in-ring debut for the company at a NXT live event in Orlando, Florida on September 30, 2016, competing in a battle royal. In June 2019, Brennan was given the new ring name, Dio Maddin.
On September 10, 2019, Maddin joined the commentary team for 205 Live, replacing Nigel McGuinness. Later that same month, WWE announced as part of their "Premiere Week" that the commentary teams would be changed, with Maddin becoming an analyst for the Raw commentary team with Vic Joseph and Jerry Lawler. On the November 4, 2019 edition of Monday Night Raw, Maddin was attacked by Brock Lesnar who performed an F5 on Maddin through the announcer's table. Maddin was defending fellow commentator Jerry Lawler after being threatened by Lesnar's advocate, Paul Heyman. He would then leave the announce team and go back to NXT to pursue a return to the ring, being replaced by Samoa Joe.
Personal life
Williams is the son of Jacquelyn and former NFL defensive end Brent Williams. He has three children with his wife Ciarra. His brother Cam played as a linebacker for Ohio State, and is currently a scout for the New England Patriots. Williams was a fan of professional wrestling growing up, having cited Eddie Guerrero and The Great Muta as some of his favorites. He is also a fan of video games, anime and manga; his current ring name is even inspired by Dio Brando, a focal antagonist of JoJo's Bizarre Adventure.
Other media
Williams has appeared in various streams on the role-playing YouTube channel The Third Wheel, most notably in the role of The Batsu Sama, the scariest person in the world. He joined the main series of the channel "Thrilling Intent", as a steely assassin named Harlock, with a bionic arm and a love for traps, as well as another series on the channel, No Smarts But Hearts, where he plays the prestigious Clover Von Krone, a warm-natured, but incredibly strong member of the elite Adventurer Knights. Williams took part in multiple collaborations with the YouTube channel Super Best Friends Play, where he earned the nickname "Better Woolie" for his resemblance to group member Woolie Madden, from which his name change to Dio Maddin is partly derived. He also appeared in a Minecraft Wrestling Show called "Minecraft Wrestling Alliance". He has also done voice-over/narration for various videos, such as "Jojo's Bizarre Adventure Part 2" by Did You Know Anime, and "Welcome to YouTube Comments - Part 1" by JelloApocalypse.
