Troels "SyndereN" Nielsen is a Danish player currently playing for mousesports.
 Dota 1
 Dota 2
 As a player
SyndereN's big break in Dota 2 came when his current team of "Wild Honey Badgers" won the Dreamhack Winter 2011 Corsair Vengeance Dota 2 tournament. Shortly after the tournament completed, SyndereN and his team were picked up by mTw to form their Dota 2 division. Despite running into a few changes with the team and even a complete revamp, SyndereN continued to prove his capabilities as a captain and a player by leading mTw to tournament victories in The GD Studio's Arena #2 for $1000 and more notably, retained their Dreamhack championship at Dreamhack Summer 2012 against Na'Vi for 50,000 SEK (approximately US$7,500).
With the same line-up as Dreamhack Summer 2012, SyndereN managed to qualify for The International 2012. Shortly before the tournament rumours started that the team had internal issues and SyndereN was removed from the role as captain. After a disappointing 3-11 record at the event all players, except for SyndereN, left the organization. It was made clear that SyndereN would, yet again, build a team from scratch.
On October 31 of 2012, mTw announced their new Dota 2 squad with SyndereN at the helm again. The new team consisted of Matrim, Tulex, Warlog, Dutch_freak and SyndereN himself. The newly established mTw team was expected to participate in DreamHack Winter 2012 on the backs of the invitation the previous mTw squad received for winning DreamHack Summer 2012 over Na'Vi. Unfortunately for SyndereN and his fresh dota squad, they were unable to attend DreamHack Winter 2012, stating that they were not up to the level of skill they wish to be. SyndereN was never able to really show off his newest mTw Dota 2 squad on a big stage because on January 27, 2013, mTw shut down for good. After that, ex-mTw played under the moniker of Re-defining Madness. On February 26th, SyndereN announced the disbandment of Re-defining Madness, due to a lack of progress and lackluster performance, and the players went their own ways.
On May 1 of 2013, SyndereN joined mousesports, where he replaced the recently removed Alex.
 As a caster
In addition to being a popular player, SyndereN has also co-cast with Tobi Wan for The Defense Season 1 and 2, along with a few games of The International 2012. He is well liked for the insight he provides during the casts as well as his good chemistry with Tobi. Some of SyndereN's most notable casts were for The Defense Season 1 finals where he flew to Germany to cast with Tobi Wan in person.
Outside of casting SyndereN, along with Na'Vi captain Puppey, is one of the experts on the talk-show TalkDOTA hosted by joinDOTA and Tobi Wan.