I wasn't terribly familiar with all of them, but I did know what most of them were capable of. Seven of them identified as siblings, all of them named after the Seven Deadly Sins; their temperaments reflected that. As for their abilities, Envy was a shapeshifter; Gluttony was capable of tearing open the front of his body somehow and consuming literally anything; Wrath had the Ultimate Eye, which granted him uncanny levels of aim and precision and allowed him to anticipate his enemies' movements; Lust, their only sister, was capable of extending her fingertips to just about any length, rendering them sharp enough to cut through any material. Sloth had superhuman strength; I wasn't familiar enough with Greed to know much about him.

Pride was the oldest, and appropriately the most dangerous. He was capable of manipulating shadows, giving them tangible form and using them in ways similar to Lust - cutting through anything - or simply grabbing people to control or manipulate them; said shadows were also capable of forming eyes, allowing him to see anything in places where shadows could logically fall, and they also had many mouths, which he would use to consume victims. He ate Gluttony that way, I'm fairly sure, for the sake of acquiring the latter's powers.

The eighth was a being known as Father; he was the one providing the largest threat to Amestris. He was trying to gain enough power to...ah, the only way I can really describe it is "become God" - to basically take the power that the forces of nature and the world itself hold. He planned on doing this by sacrificing the lives of everyone in the country.