I sort of wish I had had this sort of idea when I originally made the Danzo I linked earlier. Manda's effect was cheese, and putting it on a Reinforcement, even one with some rather steep Sacrifice, still makes it kind of a bad effect. A built in Nine-Tail's Cloak like effect, though, might have been better, and not quite so OP. Crap, now I sense another "Izanagi Danzo remake" in my future.
Maybe the new Danzo will be more like this
As for mechanics keywords, I doubt Danzo will have any. Some of them are more for low-turn, and the others... I expect the next 6th Hokage/Danzo card to be more like a set 25 card, and leave the gimmicks on lower-EC ninjas. Of course, I don't know, and if he has three elements (he should), then he might have three to choose from. Personally, though, I think more of the new mechanics are to make lower EC Ninjas more useful, or more so later on, so that you don't have to cuss when you draw them later, or they can help build into your late-game strategy, rather than "wall till turn 4". The higher EC Ninjas are more able to carry power-effects, and have more Attributes/Characteristics, thus not needing these. The Fish might prove me wrong, being a T5, but his needs you to be maybe losing, already.
If Danzo has to have Inherit, Flashpoint, or Revitalize (these should be his three elements; Fire, Earth, and Wind), Flashpoint seems best for what this Danzo would represent. Revitalize sends him away, and Inherit I would rather another Ninja have, to give Danzo some cool effect. So, I expect none, but will vote for Flashpoint, if one he must have.