plus you wont even be able to get to him with out other friends.
even before you get to his door the other two bosses are like around 7500 hit points and then to open the doors to the great spyre you have to activate 3 crystals all at the SAME TIME. Then when you get to the main doors leading to Malistaire there are two gards one on each side of the door. To get the doors to open they have to be killed at the SAME TIME.
So you have to have at least 3 people to get to him.