Elektra Natchios was an ordinary woman who became a martial artist during her late teens/early twenties then later on becoming 1 of the most deadliest assassins in the world. Even though she was defeated by the psychotic, animantium Bulls-Eye with her own sai she was able to come back even stronger 2 defeat him in battle. She can very well hold her own against DareDevil and she also bested Catwoman (Selina Kyle) in battle during the DC & Marvel crossover. Elektra trained in various styles of martial arts and is very skilled in different types of weapons (melee & machine). She is acrobatic and possesses an extreme, low level of telekinesis. Elektra is aslo highly in control of mental & physical pain (enable 2 numb her body and reduce bleeding mentally).
Since the day she was born Cassandra Cain(the recent former Batgirl) was trained by her father David Cain(the most deadliest human weapon in DC who also trained Batman/Bruce Wayne) 2 be the most deadliest human weapon in the world. When she was 9 years old her father ordered her 2 kill a man using the technique pressure points; terrified after-wards she ran away from home traveled the world and continued 2 learn different styles of martial arts. When she was 17 years old she met Batman and from then on he continued 2 train her in more styles. She killed Nyssa Raatko in battle and also bested her own mother Lady Shiva(the deadliest human woman in DC universe) in battle by breaking her neck. Cassandra trained in various styles of martial arts and assassin techniques since birth and managed 2 create combat moves of her own during her training. It is 2nd nature 4 her 2 predict the next attack from her opponents due the side effect of the brutal training her father put her through. Cassandra's immune system is so strong 2 the point where she is highly resisted to most poisons & toxins and can endure extreme, physical pain (enable to ignore the shock of multiple bullet penetrations while still in combat for a long period of time).
Both of these women is not 2 be played with so who do think would win in a 1-on-1 battle in hand-2-hand combat 2 the death ?
P.S please don't let favoriteism and popularity decide which woman is the better combatant, be HONEST.