No doubt that you heard that Elektra fights Bullseye. It happens in Daredevil 181 (Affiliate Link), and it results in one of the most infamous series twists in comic book history. Elektra fights with a sai and Bullseye fights with a gun, however their common trait is that they were both assassins working for the Kingpin.
The plot of Daredevil 181 is that Bullseye breaks out of prison after the Punisher alerts him that he had been replaced as the Kingpin’s top assassin. He discovers that the new assassin is Elektra. The result, of course, is Elektra vs Bullseye. After much fighting, Bullseye kills Elektra but slitting her throat with a playing card, and then stabbing her with a sai.
Bullseye also discovers that Matt Murdock is Daredevil. The way he finds out is so simple, it’s kind of funny. He noticed that they looked similar. So to test his theory, he throws a knife at Murdock. When Murdock blocked the knife with his stick, it confirmed it. All it took was simple recognition, and just throwing something at him while his back was turned.
Frank Miller’s art always amazes me, because his style varies by a large margin. His artwork in Daredevil 181 is perfect. There are some panels where he has close-ups of faces, and they look phenomenal. The characters he drew have perfect shape and anatomy. Compare this to his work on Sin City, which emphasizes light, or to The Dark Knight Returns which has abstract, sketch-like characters.
The Elektra vs Bullseye scene in Daredevil 181 was such a critical part of comic history that if you ever come across it, you definitely want to give it a read.