It's a strong ult. IMO it should come with a Fort audio cue for the other team to hear (like every other ult in the game) when he puts it down. This would keep it balanced. Not that it's overpowered, but it shouldn't be silent when every other ult comes with audio, especially to be able to locate the bomb. my 2cents
U can plant a bomb which goes off in 8secs i guess dealing some damage and stunning enemies within range. It also has some health around 9000hp(almost health of a tank character). Enemies can shoot it to destroy or defuse the bomb(so it wont go off).