Arguably the most loyal to Sensui after Itsuki. He appears to be very secretive and doesn't speak unless necesary. His ability involves placing his ki into an object and firing it at a person; he can affix targets to a person's body so that it is impossible for him to miss.
He comes back to life after Kamiya heals him, and we last see him with his sister, avenging the death of a kitten.
Seemingly a kindly doctor on the outside, Kamiya-sensei turns psycho when he encounters the protagonists- unleashing a deadly virus on the hospital and making his body function at a superhuman level. Yuusuke found him difficult to kill after realizing he was a human being, but after showing off his freakish modifications (reattaching his own limbs, controlling the endorphins in his brain), Yuusuke put him out of commission. Later in the series we see he is on trial for a serial murder case; he then escapes from prison and disguises himself with his abilities.
Seaman's abilities involve mixing a drop of his blood with liquids (usually water) to create monsters. The more blood that is added, the straonger and larger the monster. He was defeated by Kuwabara with his Jigen-tou, and was taken to Yuusuke's apartment for healing. He was the only member of the Seven who had the brains to get out of Sensui's cult and acknowledge that humanity isn't all bad, which is why I like him. (That and he's adorable in a little-kid sort of way.)
This guy has the ability to gain other's powers by eating them. Unfortunately, Sensui asked him to eat someone that disagreed with his stomach and took over his body...
Ananuma's ability is to make any game he chooses to play a reality; the other contestants die if they choose not to continue the game. However, Ananuma loses, not knowing that Sensui was using him as a pawn until Kurama told him. (Honestly, the first time I saw this kid, he scared me; I thought he was a bratty otaku. THEN I saw his realization, and that broke my heart and changed my mind @ him.)
Koenma brings him back to life using the Mafuukan, however, and we last see him actually making friends through his love of games.
