Pride- The Leader

At first Pride remains hidden, and only his voice is heard when he talks to (or rather scolds) other Homunculi. "Selim Bradley" reveals his identity to Riza Hawkeye in chapter 70. Shortly after, he orders Solf J. Kimblee to carve a blood crest on Briggs, before having a short fight against Hohenheim in the tunnel for the country-wide transmutation. During later chapters, he personally enters the fray helped by a newly reborn Gluttony. He captures Alphonse Elric and takes control of his armor with his shadows, using him to lure Edward Elric. He and Gluttony then engage a fight against Ed, Greed, Darius and Heinkel, and soon joined by Lan Fan and her grandfather Fu, during which he devours Gluttony gaining his appetite and his sense of smell. He soon overpowers all his foes, but he is ultimately trapped alongside Al in a huge domed jail of earth by Hohenheim.
Now unable to use his powers because of the absolute darkness in this jail, he and Al had a discussion about being human where he admits to be truly fond of his adoptive human mother. This, and his apparent closeness with Wrath seems to show that he is not entirely devoid of human feelings. Yet he may only be pretending or biased, as he shows no compassion towards Gluttony, cynically referring to him as a "part of a system" instead of a sibling. However, by banging continuously on Alphonse's helmet with a stick, Pride sent a message in Morse code to Father who summoned Kimblee to his location. There, Kimblee's alchemy set Pride free, severely wounding Heinkel in the process. This engaged another struggle with Pride and Kimblee against Alphonse (with a Philosopher's Stone), Tim Marcoh and a healed Heinkel. When his opponents managed to flee, Pride was left with a dying Kimblee whom he devoured, further enhancing his power to a yet unknown extent and gaining a third Philosophers stone.
In chapter 101, Pride reappears in Father's subterranean lair, confronting Roy Mustang's group alongside Wrath. He rescues the Alchemist doctor from Jerso's grasp only to stab him with his shadows shortly after. He then activates the transmutation circle, where Wrath has trapped Mustang, making the Flame Alchemist the final Sacrifice needed.
He is now facing Edward and Alphonse, in battle although seemingly at a disadvantage. It appears that when he forced Mustang to perform human transmutation, he paid a price as well, appearing to be weakened in using his shadows in combat. This is noted by the Elrics when he jumps to dodge an attack, rather than use his shadows to counterattack. His face also seems to be disintegrating.
Edward and Pride proceed to have a battle, in which Pride moves in to fight close combat. However, Pride is not able to block attacks with his shadow, and seems to only be able to make medium-powered attacks with his shadows. However, when Pride underestimates Edward, and Edward headbutts Pride's face, a large chunk of Pride's head seems to disintegrate, much like how the other Homunculi disintegrated when they died. This may suggest that when Pride went through the Gate with Mustang, Pride paid his toll by giving up all his spare lives there, which would considerably weaken him and also cause him to start disintegrating. However, this is just a theory.