Help! Is this a new concept or done before?

I've hade this idea rolling around in my brain for a while and I am trying to figure out if I made it up or I'm "borrowing" from a source and can't remember which one. At least that is my main question.

The Concept:

What I am looking for is a system that at least feels a lot like "channeling" power. Building it up so that the player knows they ARE going to hit, and hit big, when they are ready. No rolling a 4 on the crucial final blow and dragging things out.

The idea is to allow players to build up power then spend that power to do exactly what they want. One game I know of that does this is Mythender. In that game you roll dice to build up power. I think you rolled a pool of Storm Dice, and any successes bought you Lightning Tokens. Then you spent the tokens to do your cool stuff like damaging the enemy or creating field effect.

Another game I remember hearing about was Gumshoe. In that game you played prepared characters. Skilled detectives and investigators that could spend a resource to achieve their stated goal, or roll randomly and conserve the resources for future encounters.

What I am asking for here:

What I'd like is to know if there are any other games out there with similar mechanics that I just don't know about. I'm intending to go into these games, the ones I mentioned and any suggestions here, to figure out if they are the system I want, or if I should try my hand at creating something from the ground up.

I have never played the two mentioned, only read about them. Mythender is closer to the vein I'm thinking with its cool god PCs, but the structure is too rigid in my mind. It might just be that I've not seen it in action for myself though.

Gumshoe might be what I'm looking for, but it doesn't seem to have enough flair for what I want. Perhaps it's a limitation of my exposure. Like if you know of a Superhero, Super-sentai, or magical-girl version using Gumshoe, maybe that would help.

I don't know that I have it in me to make a whole game, but I know what I'd like to see and I don't see it yet. If you think you've got an idea, your input would be appreciated.

Darn it, I was going to suggest Mythender but then you already brought it up...
I played in a superpowered game of Gumshoe using Mutant City Blues, but it was still mostly investigation focused, so I'm not sure if that's what you're looking for.

I'll think about this some more.

Any system with 'Bennies' or such points you can hoard and dump in one big spend can do this 'build up for a big, guaranteed hit'. Savage Worlds and Fate come to mind as ones that could fit your proposed idea.

Yeah, Mythender is fun and it might just need a genre switch to be what I'm looking for, but it's lack of "small actions" also kind of throws me off. I want to be able to do things that aren't killing gods, or building towards that, with every action. Some persuasion and Stealth at times.

I will look into Mutant City Blues though. It's a step toward what I'm looking for.

And of course further thoughts are always welcome.

Fate! Yes. That's another example of what I'm working towards. Can't believe I didn't think to mention it. Working up to a pool of Fate points is very much inline with what I'm thinking. I'm going to add Fate Hacks to my list.

Savage World's however is unknown to me. I've heard of it of course, but never really played/read up on it. I'll have to see how it works.

I have recently been looking a bit into Belonging Outside Belonging, which might also something you could be interested in. That system has no randomization and the way it works is that by doing "weak moves" (making yourself vulnerable, messing up...), you gain tokens that you then spend on doing "strong moves".

I haven't gotten to play any system in that engine yet, but I really like the concept of it.

You can also take 'small actions' to build up Aspects (scene or otherwise) to load the final confrontation in your favour.

And, if your Playbook (class/profession in other games) has the more, "Kill Someone" might be that Strong Move, and then that just happens.

Belonging Outside Belonging might not be a good fit here, since you can only spend one Token at a time, and are then limited to the specific Strong Moves you have. So it might not be granular enough.
I have 'run' Dream-Askew (old and new version) and Dream-Apart, and dabbled with some of the other, third-party, BoB systems. If we have the right group interested in something like that I could facilitate or run one here.

Not to derail this thread, but I would definitely be interested. I have been thinking about trying to start a game of Dream Askew (or maybe Sleepaway, though I haven't actually looked at the game beyond its description) on here. The only thing that stopped me so far is that I think you need a strong player investment for these and that can sometimes be difficult to achieve/maintain in pbp.

I'm always interested in trying new systems.

Do you know about Momentum mechanic in 2d20 systems? Especially in Conan? It could bring another pov on the subject I think.

I don't. I played Star Trek 2d20 and don't remember that, but we were all brand new. The GM may have missed it.

Anima Prime has a similar system where you have 3 pools, and you can divide your dice between them for things like defense, regular attacks, and special abilities. I've never played it and read it years ago but I remember it sounding cool how you can assign dice to different actions and how they pools get bigger as combat goes on.

That's interesting. On my list.