I'm in the saddening position of needing to replace Vader because he's grown stagnant. I can't increase his stars or gear any further and he's the weakest member of my team. In order to replace him I'll need to build another character up. My current team is a 5 star Sidious gear lvl 7, 6 star Luminara gear level 7, a 6 star Jedi consular gear level 8, a 5 star Kylo Ren gear level 7, and then Vader at four stars gear level 7.
The characters I have that I can replace him with (after gearing them up) are a 5 star Tarkin, 5 star Ahsoka, 6 star Cad Bane, 5 Star Ventress, and a 5 star Leia. Who should I use?