I don't actually want to completely avoid a power list per se, I just want to avoid three pages of dense text describing every individual power in the known universe. I think once I have categories of power decided on, two or three example powers for each would be more than sufficient. I think the idea would be that some base mechanics are laid out, along with some examples, but after that its up to the player and GM to define the exact nature of the powers. That shouldn't be too much of a burden when its tag based, and I can steal some of the verbiage from CoM about overly broad tags and whatnot.
I suspect that powers will be a complete 'chapter' of the rules. I want that to be more about the narrative uses, setting how they function in play, and outlining progression during play, than about lists of actual powers. I really dig the division of powers in CoM into themes, and I think I want to steal that. There are 8 themes total, and that seems manageable, and has some nice symmetry with the number of playbooks. It's almost a 1-1 relationship between the playbooks and powers actually. Since you would be able to dip into more than one power that really opens up the variety in how characters get built.
On to stress. Yeah, I had thought that this seemed like a high stress-use kind of game. I'm not 100% sure how to manage that. I like compelling weaknesses in return for reduced stress, but I don't know if that will enough. It's not like anyone wants their glaring weakness coming up 4 or 5 times a job. One possibility is to lengthen the stress track a little, and another is to keep the stress costs down as much as possible. One way to reduce the stress use is to have basic power use not require it, but require it for 'souped up' actions. So you flaming fists add a die to melee, and you can burn a stress to have them also grant potency for the duration of combat. Something like that.
One thought I had along those lines is to add some dramatic tension to the game by having two mechanics that really pull the characters in different direction. Since we're talking villains, I think at least some of the XP triggers should be very personal and individual, and perhaps quite different from playbook to playbook. If, on the other hand, some of the mechanics for powers emphasized teamwork and cooperation to help mitigate or reduce stress, that could produce a nice push and pull between individual goals and team success. Especially if those system were purpose designed to work together to get the desired push and pull. I don't know if this exact example will provide the tension, but the more I think about the more I really want that tension in the game somewhere, somehow.
Specifically on XP, I'll say I'm not sure. The baseline is obviously Blades but that may change a little once the details start to emerge. One thing I'm considering is either decoupling XP from the attributes and make it more personal beliefs and mission state oriented, or keeping the attribute XP and extending it to powers somehow. Powers could simply be treated as additional attributes, but since they are used in conjunction with actions, where do you put the XP for desperate actions, on the attribute or Power XP track? The option I'm currently looking at the hardest is to keep attribute XP the way it is, but tie power XP to personal belief and goal type stuff. Generally, your actions get better from desperate use, and your powers get better by following through on your core drives and motivations.
I want to add to the diversity of the playbooks. The abilities will be at least the same as S&V or BitD, and then I want to layer on powers and probably weaknesses. Figuring out XP triggers will be key, once I figure out exactly what the abilities, powers and whatnot look like.
