you would have to go full villain, run a patron arc and respec, they should be permanently unlocked once you run the arc so they should still be available once you go back blue and do a respec on blue (they will definitly not go away if they were picked powers if you respec on redside)
Also, remember that running any one of the patron arcs will unlock *all* the patron pools, so you don't have to worry about having to slog back through another side switch and another arc if you just want to change pools.
Currently have a Mastermind playing hero side and need some help on how to get Patron Power Pools for someone who has never played villains much. Do I have to switch to vigilante or go full villain? Then there are some missions I have to do to unlock them?
Also, if I get the patron power pool, go back hero side, then respec will I still be able to choose them or would I have to switch sides again to choose it?
Thanks in advance.