What happens to Obito after the 5 minutes of intangibility? Obito is intangible. This intangibility last for 5 minutes. After 5 minutes, what happens? I am confused.
Or does  he needs  to keep phasing  through  objects  to remain  intangible?
Normally, Obito is not intangible. When he uses Kamui, he can teleport the parts of his body getting hit by attacks into the Kamui dimension, stopping himself from getting damaged. However, the limit of the justsu is five minutes and that is the maximum amount of time he can continually use the jutsu. After the five minutes are up, any further attempts to use Kamui fail, and he presumably requires some time to recharge his chakra before using it again. Your question was kinda confusing, so sorry if I didn't answer properly.