PoD Bane vs. S5 Ventress

Who wins, the young Dark Lord or Dooku's assassin?

Ventress quite handily

No.

Ventress as Dooku's assassin would lose, because it's early CW Ventress so she ultimately loses

Bane wins this one. His performance against Kas'im speaks for his skill and speed as a duelist

His choking Qordis to death and collapse of the Rakatan temple as well as various accolades speak for his force ability.

He's also a very tactically creative fighter even by this point.

Bane, rather easily

Bane in a good fight, he has greater strength and power in the Force.

Bane fairly easily