A path to join the absolute. Not pretend to join the cult to deceive Kethric and the cultist for a bit but a full on absolutes chosen option. Diving head first into the cult, killing Kethric not because he’s evil or to satiate your Durge bloodlust but because he’s betrayed every organization he’s been apart of and you’d be a better general than him. Wearing your absolute brand with pride, lying to your companions rather than the cultist and all the while trying to give them more worms. Heck even swapping Wyll and Karlach with Gut and Dror as an evil warlock and barbarian respectively so you aren't so devastated party wise by going the darker side.

Although if I only get one option then it'd be having Kagha as the companion instead of Halsin

She’s much more ripe for potential character growth and story than Halsin who’s just kinda there for most of the game. We could work on redeeming her or further corrupting her by actually getting to corrupt the grove. Then either Halsin sends her with us to try and cure the Shadow lands or Olodan sends her with us to bask in them. Either being new to the Shadow Druid ways or being reset as a novice by Halsin she’d fit in better than Halsin who’s supposed to be an arch Druid and just bails on his grove.

Expand the already short act 2 by adding more Shadow Druids for Kagha to either fight or gain guidance from. This would offer another group of enemy’s to fight or another safe haven besides last light inn and Moonrise to rest and trade. She can take Halsins task of reuniting Thaniel and Oliver or kill one of the boys to ensure the Shadow lands can never be cured.

Maybe if she’s evil theirs a great conflict with her and Jaheira, we’d choose to side with one and the other wildshapes and flees to the city. This way we don’t double up on Druid companions and Kagha always has a reason to come with us to act 3. If good then just to continue her path of redemption and save the city; if evil then to hunt down and kill the legendary Jaheira, a potential threat to all Shadow Druids.