Question: when did angel start in relation to buffy

title: Angel (Buffy the Vampire Slayer)
text: In season two ( 2000 -- 2001 ) , Angel discovers that Wolfram & Hart has brought his sire and former lover Darla ( Julie Benz ) back from the dead in human form . Although Darla is intent on bringing back Angelus , Angel hopes to save her soul and help her seek redemption while she still has a chance . However , just as it looks like he might succeed , Wolfram & Hart bring in Drusilla to turn Darla back into a vampire . Angry at the lawfirm and embracing his darker side , Angel fires his employees , Cordelia , Wesley ( Alexis Denisof ) and Gunn ( J. August Richards ) ( secretly to protect them from this dark territory , as he later revealed to Lorne ( Andy Hallett ) ) , and embarks on a vendetta against Wolfram & Hart , even allowing Darla and Dru to massacre a group of lawyers . Eventually losing faith in his mission , Angel has sex with Darla in the hopes of losing his soul . Instead , he experiences an epiphany and realizes that the good fight is still worth fighting . A disgusted Darla flees L.A. and Angel reconciles with his friends , who eventually forgive him . Angel also appears in Buffy season five 's `` Forever '' , comforting Buffy after her mother 's death .