Kim Taek-yong, known by his screen name Bisu[Shield] or simply Bisu, is a South Korean professional StarCraft player, playing the Protoss race. Famed primarily for sublime performance in the StarCraft: Brood War professional competitions against Protoss and, especially, Zerg, Bisu scored three successful Starleague performances, the most of any Protoss player. Bisu was nicknamed the Revolutionist for innovating the metagame of Protoss versus Zerg matchup.

Since his transfer from MBCGame HERO to SK Telecom T1 team in 2008 Bisu, along with Stork, has been leading the Protoss players and both were called "Twin Carriages". Bisu is ranked 2nd in the Elo rating system. In the 2010 Team Liquid forum poll Bisu was voted "the greatest Protoss player of all time". He retired from Starcraft II in 2013. After retirement, he started his personal broadcast by Afreeca TV. Bisu also participates in AfreecaTV StarCraft League.

Kim was born in the South Korean county of Yesan. In his early years, before moving to Seoul, he lived in the city of Cheonan with his home being next to his school. Since childhood, however, Kim did not favour studying and became gradually addicted to computers in grade school. He also used to play soccer "until the sun went down" and has been always picked first during team arrangements; he wished to become a soccer player, but following his growing interest in video games, Kim quit playing soccer and his soccer experience slowly faded away. Kim started playing StarCraft while in the fourth school grade and up to high school has been the most experienced player in his class. Before choosing StarCraft Kim tried Lineage and Fortress, gaining some experience in the latter. Because he became a professional gamer at age 17, Kim was unable to attend an institute of higher education. He lately entered Sejong University.

Kim considered becoming a professional gamer as a freshman in high school. He began playing StarCraft: Brood War when one of his relatives took him to an internet café. As a newcomer Bisu used to watch others' games and particularly liked those of NaDa, as well as Nal rA's strategic gameplay. Nonetheless, Bisu did not have any particular role model and wanted to emulate all great players. During Bisu's MBCGame HERO (Pirates of Space at the time) years his gameplay was largely influenced by Protoss player Pusan, whose games Bisu frequently watched. Bisu's coach and player Best in turn taught him everything related to Protoss builds.

Having participated in high-level competitive matchups since 2006, Bisu made his breakthrough at the 2007 MBCgame Starleague (MSL) final, defeating experienced players Nal_rA and sAviOr, both 3:0. At that time Bisu was one of the few Starleague Protoss players. He qualified for the 2007 MSL automatically for having received a KeSPA distinction as the best Protoss player. Prior to the breakthrough match with sAviOr, which is sometimes referred to as "March 3rd revolution", Protoss players generally underperformed against Zerg. However, this was soon to change. During Bisu's preparations for the match with sAviOr, the MBCGame HERO coaching staff, as well as Protoss and Zerg players gave Bisu some ideas. The general advice was to use Corsair units to eliminate Zerg Overlords, narrowing Zerg's observation. Bisu's effective execution of this strategy found great success. Following Bisu's victory, several players started to emulate his winning Corsair–Dark Templar combination to fight Zerg opponents.

In the first half of February, 2008 Bisu (who was already atop of the KeSPA ranking, the first protoss to achieve that) was transferred from the MBCGame HERO team to SK Telecom T1. The latter team failed to score good results in leagues and confront the new generation of professional gamers, and the entire coaching staff was dismissed. Players iloveoov and Kingdom were promoted to coaches instead. To fill the gaps and to improve the performance results, SK Telecom T1 acquired Bisu. Bisu later called his transfer "definitely a turning point" for him as a gamer. In 2009, to fill up the schedule, OnGameNet arranged an All-Star Race Battle, where four players of each race (Protoss, Terran and Zerg) would compete in a knockout series. Bisu defeated the Terran lineup of players Flash, Hwasin, Leta and NaDa, but failed to score a win against sAviOr.

In the fall of 2008 Zerg players adopted a three-base five-Hatchery strategy against Protoss and nearly all attempts to counter it failed. Protoss players had particular difficulty using Zealots against Hydralisks in a choke battle as the Zealots could not spread out effectively, while Hydralisks could clump easily, not allowing Zealots to take advantage of their speed upgrade. Bisu managed to successfully use speed-upgraded Zealots to obtain map control and engage the Hydralisks before they reach mass numbers. While other professional Protoss players have around a 60% win ratio against Zerg, Bisu's ratio against that race reached over 90% in the 2010–2011 competition season. During the 2010–2011 Shinhan Bank Proleague Bisu also achieved the largest number of wins. In the past, however, Bisu was not particularly favored against any good Zerg player. On April 2, 2011, Bisu, having defeated Jaedong in the Shinhan Winners League playoff, broke what he called "a vicious cycle" of his Protoss versus Zerg gameplay. He once revealed, that only after learning the skill of combining different units (i.e. ground, air, high templars, reavers) he began to enjoy playing against Zerg.

Bisu's matchup against Protoss players is statistically in the middle between Zerg and Terran and could be traced back to 2005. From then and until February 2006 he had been in a 3-loss streak against Protoss players and played with intermittent success until the matchup with Nal rA. In February 2007 Bisu achieved a 3-win streak against him, which contributed to Bisu's uninterrupted 6-win streak against Protoss in the same year.