A lot of people dont realise that Dark Orbs always hit the target with the lowest health. He mentions it at the second boss. It isn't Dark Orb luck. If you hover your mouse over the Dark Orb effect, it'll be explained as well.
I agree, only orb build is viable in A20 honestly. I tried forcing non-orb decks (All For One + Streamline + Reprogram + Claws) many times, still not beating Act 2 and 3 consistently even with a good deck. The hardest part about Defect is to get those specific orb related powers to scale up quickly, while trying to stay alive for the first few turns.
this shit little bird is the reasion i dont play robot i think power builds are cool BUT when the act 3 boss says u cant play your build or u die it fking sux the timelord has atleast counterplay to spam builds with by shivs for example finisher but when your build is paly powers to get more stuff and u cant play your powers because he muliatacks u for a billion then idk