A few days into a new game always seems to be the most confusing. You are beyond just the intro stuff and trying to figure out all the variables and parameters.

So I have a decent crop of general purpose characters now, with my team heavily built around healing and support. One thing I am noticing though is that it is very helpful, especially in some challenges, to have something that removes buffs from enemies or debuffs from allies. What are good characters for this that are also good in their own right?

One that I do have from the pack I bought is Asajj Ventress. She comes as a 3-star with enough shards to promote to 4-star, but I haven't used her much yet. Is she worth promoting/gearing/training?

Who else? Needs to be something I can build up by gameplay. (I am not averse to spending $ on the game but will not spend hundreds on card lotteries.)

Thanks.