blue credits - where are they?

[etnin]

Are they just randomly in the small chests?

[thenameles12345]

rarely in their own blue chest similar to a coin chest that give 4. Occasional find them on dead wardens gives 2 I think. Lastly doing the small black portals and killing all the enemies that spawn from it will grant 2 and is the main way to farm that material

[S20G Treble]

They mostly drop from Chests, fallen Wardens and Elite portals. I think there is some kind of rollover conversion from unspent yellow or green bits, but I am not sure about that. My best run so far I've gotten about 200.