He released the album '' Ultramania '' which consisted of nu metal and Hardcore punk . His solo act had an effect on many South Korean boy bands such as H.O.T. and caused them to decline in popularity . His songs " Internet War " and " Ultramania " were the biggest hits of the year . After the first ETPFEST in 2001 , which he founded during his comeback , Taiji was presented with hide of X Japan 's Fernandes MG-360S guitar , which is yellow with pink hearts , by hide 's parents and his brother , Hiroshi , to celebrate the success of ETPFEST and the first hide showcase tribute ever at a Korean rock festival . During his comeback , there were arguments that his seldom appearance on TV was aimed to make a mysterious image which helps promote his popularity , but in reality his personality is very reclusive and little is known about his personal life by the public . He has mentioned in several interviews that he chooses to maintain private personal life separate from his musical career but this concept is never well-accepted by the Korean culture where celebrity personal profiles are often widely disclosed to the public . This is one of the few reasons he is criticized as being a mysterious figure
ETPFEST
ETPFEST
Seo Taiji