NEW YORK — Rihanna on Friday described the horror she felt as her ex-boyfriend Chris Brown was biting and punching her during a violent argument in February, saying she saw "no soul in his eyes."

"There was no person when I looked at him," the 21-year-old singer recalled during portions of an interview with Diane Sawyer airing on ABC's "20/20" and, earlier, "Good Morning America." ''He had no soul in his eyes. Just blank."

Brown was arrested Feb. 8, hours after he was accused of beating Rihanna after the two argued over another woman. The singer later pleaded guilty to felony assault.

In the interview, Rihanna, who is no longer with Brown, described him as "definitely my first big love." She said their relationship was intense.

"The more in love we became, the more dangerous we became for each other — equally as dangerous," she said. "It was a bit of an obsession almost."

The attack occurred in Los Angeles' Hancock Park neighborhood as Brown drove a rented sports car. She said it was triggered when she saw a text message on his phone from another woman and confronted him about it. She said he lied about it and "I wouldn't drop it."