The Canadian tactician will be replacing Brandon "Ace" Winn on the roster and taking over the in-game leadership duties from Skyler "Relyks" Weaver, who makes the transition to primary AWPer on the team.
With FNS' addition, eUnited hope to improve their tactical flexibility, after their most recent LAN outings ended in disappointment. The North American side finished 7th-8th at DreamHack Open Montreal and in third place at the four-team MSI MGA Finals.
During his time leading Cloud9, the ELEAGUE Major Boston champions reached the playoffs at DreamHack Masters Marseille but crashed out in the groups at IEM Sydney and at the offline finals of ESL Pro League Season 7 and ECS Season 5.
The Canadian player was full of praise for his new teammates and organisation, and spoke of his intention to guide the squad to the top.
"Not competing for the past two-three months has been difficult but refreshing in a sense," he told HLTV.org. "It gave me time to reflect on everything that went wrong with C9, but I am happy they found a lineup they are confident in.
"As for me, I couldn't be more motivated up to get back in the server and play with this group of talented players. This game has been my life for the past four years, and I can't wait to show everyone what this team is capable of.
"I have the complete respect of every player/coach on this team and so far, the organization has shown me nothing but love. That's all any player can ask for, and I am grateful for this opportunity.
"For all the people who have consistently supported me, whether that be family, friends, fans, ex-teammates, whoever, I really do appreciate it. Over the last couple of months, I've received tons of positive messages, and I'm genuinely thankful for that."
FNS will make his first LAN appearance for eUnited early next month, at IEM Chicago, kicking off November 6. Two weeks later, the team will compete at DreamHack Open Atlanta, for which they qualified after beating Spacestation in the grand final of the closed qualifier.
With these changes, eUnited now have:
Jared "osorandom" Hartman (coach)
Brandon "Ace" Winn (bench)