Cloud9's owner Jack Etienne looks back on 2018 and the success his organization has had throughout the year. (7:44)

Cloud9 announced the signing of Blue "Blue Buff" Sentinel to their League of Legends roster.

Blue Bluff helped lead Cloud9 to a 3-0 victory over Afreeca Freecs in the quarterfinals of the League of Legends World Championship over the weekend, and the organization tweeted out his official signing later that day.

"Please join us in welcoming Blue 'Blue Buff' Sentinel to the #C9LOL Team!," the organization tweeted. "We're excited to have it join the #C9FAM after an exceptional performance in the #Worlds2018 Quarterfinals match and we can't wait to see more!"

In Game 2 of Cloud9's quarterfinal match against Afreeca, the neutral objective landed the killing blow on Afreeca jungler Lee "Mowgli" Jae-ha at 20 minutes after Mowgli was nearly killed in an ambush by Cloud9 top laner Eric "Licorice" Ritchie, support Tristan "Zeyzal" Stidam and jungler Dennis "Svenskeren" Johnsen. Cloud9 went on to win the match and sweep Afreeca to become the first North American team in the League Championship Series era to make semifinals at worlds.

Blue Bluff's signing came after a short trial period with the team.

"Blue Buff has shown to be more than capable of showing up and performing on the biggest stage," the Twitter statement read. "Blue Buff has already been a huge part of making North American history, and we can't wait to see what it can bring to use in the future with Cloud9!"

Cloud9 is scheduled to take on Fnatic in the semifinals on Sunday.

-- Field Level Media