With the huge success of "No-brain Survival", he eventually become an official member of top-rating comic variety program Infinite Challenge since March 2006 and as the second eldest member, he is positioned as "the third-in-command" (3인자), putting him below the host-in-chief Yoo Jae-suk and fellow co-host Park Myung-soo.
Dengan kesuksesan besar dari "No-brain Survival", dia akhirnya menjadi anggota resmi dari program variety peringkat atas Infinite Challenge, sejak Maret 2006 dan sebagai anak tertua kedua dari seluruh anggota, ia diposisikan sebagai "pemimpin ketiga" (3인자), menempatkan dia di bawah kepala host Yoo Jae-suk dan sesama co-host Park Myung-soo.