Purification or Regeneration?
I believe as I have Gunnar,for me is 2nd option… 
What other team options are great with Richard? 
If you are talking about his costume, then I’d advise you to go defense>health>attack.
But your question is unclear, what do you mean by purification or regeneration? Both costume and non costume rigard cleanse all ailments from allies.
Aren’t those two a costume depending on how you put emblems?
Right,I see…not really understood you,but advice taken 
thanks