His exploits with the amber-and-blacks were enough to attract the attention of Dave Rennie and, after Aaron Cruden suffered a season-ending injury, McKenzie enjoyed numerous chances to impress.
While showing plenty of promise, McKenzie was unable to lock down the jersey and was left out of the side as the Chiefs lost their Super Rugby qualifier against the Highlanders.
With Cruden set to return next season - and with younger brother Damian seen a stronger long-term option - McKenzie has opted to seize an opportunity in Blackadder's side, although the coach wasn't about to pigeon-hole the 22-year-old as a No10.
"One of Marty's strengths is his versatility, with the ability to play almost anywhere in the backline as well as kick goals," Blackadder said. "We see him primarily as a first five and know that he is keen to get more playing time in that position.
"He was outstanding at first five for Taranaki last season and, at just 22 years of age, there is plenty of untapped potential in him yet,"
McKenzie and Mo'unga will be teammates in 2016 but were playing first XV rugby against each other just five years ago. Mo'unga, 21, has been contracted to the full squad after spending a season with the wider training group.
"We've been watching Richie develop since he was representing St Andrew's College," Blackadder said. "It was clear then and it still is now that he is a special talent and we look forward to helping him continue to grow his game and build his experience."
Volavola, meanwhile, is moving from the Waratahs, having made eight appearances for the Sydney-based side, to also join the Crusaders' competition. Blackadder saidassistant coach Tabai Matson had suggested the Australian-born Fijian would be a valuable addition to the squad, as an athletic first-five with impressive pace and a handy kick.
"We are excited about the potential we can see in Ben," Blackadder said. "He has all of the makings of a great player and is itching to get some more game time to show what he's got."
