Talia al Ghul and Elektra Natchios are incredibly similar
The League of Assassin and The Hand are incredibly similar
Similarities:
Both secret ninja organizations that are super old
Both obsessed with resurrection/immortality
Talia and Elektra often (but not always) have a very complicated relationship with their fathers/father figures (Ra’s for Talia, Elektra’s father and Stick for Elektra)
Talia and Elektra are love interests whose relationship with Batman and Daredevil is doomed
Both have periods where they are more heroic/anti-heroic (Talia in Death and the Maidens, Elektra in the current Daredevil run and many other points when she works for the Chaste/partners with Daredevil)
Both Talia and Elektra tend to have agency taken away from them a LOT
Both Talia and Elektra have periods where they become leaders of factions or the whole of the League/Hand
Differences:
No Ra’s figure in The Hand - Stick has some of the same kinds of resonance, but isn’t really the villain or the head, and of course the Beast has as many differences as similarities to Ra's.
No “Chaste” equivalent for the League of Assassins, though they’ve been multiplying "schisms" recently (last decade), with Leviathan, League of Shadows, and League of Lazarus
Talia and the League created in 1971 by Denny O’Neil, Elektra and The Hand created in 1981 by Frank Miller
The League of Assassins is basically run for ecoterrorist reasons, though Talia’s reasons tend to be much more about power rather than her father’s ideological motives, while the Hand seems to be much more just about power and...Cthulhu stuff