The problem with Invention, as well as many other Abilities in OVA, is that you have to cover a wildly divergent spectrum of possibilities with a single paragraph of text. If you give too many details, you end up closing off certain possibilities. If you give too many options, you end up with an Ability with an overwhelming set of rules for an otherwise comparatively simple game.
So that's why a lot of the text is vague. If you want it to mean "Only two inventions on my person" it can. If you'd rather it mean "two inventions maintained at any time," it can mean that, too.
But, for the sake of it, I can try to explain how
would apply the rules as written.
Father of Dragons wrote:First, what exactly is meant by keep up with? If it means maintain under constant use, thats a fairly hard limit (two). If it means keep track of, or carry around, it isn't.
I intended it to be "readily available" yes.
Father of Dragons wrote:Can inventions be loaned to other characters?
Theoretically, though I'd discourage it. Of all anime inventors I've seen, I saw very little invention hot potato. You can explain it away as most inventions are too complex for use by non-inventors, or that inventors are possessive of their tools.
But if a certain dramatic situation calls for it, by all means. It's not glued to their person, after all. (Or is it?)
Father of Dragons wrote:Is there any advantage to making less powerful inventions? My first approach when a player took the Invention advantage was to limit them to their rank in the inventions ability in use at a time. The problem with this is that the ability goes up in power in a very non-linear way: having four inventions capable of duplicating a +4 ability is much more than twice as powerful as having two inventions that duplicate a +2 advantage. And what about the Invention, Focused ability? Does it give twice as many inventions?
There's no advantage, per se, but due to GM fiat, regularly pulling out whopper inventions can turn around and bite you you know where. They could need parts or constant repair, or be of cumbersome size. Not to mention that when they don't]/i] work, big inventions are prone to have big explosions. If you need a flashlight, you don't really need a +5 one, do you?
As for making a concrete number to work with, you could always go with something similar to the Flunkies route, where you can have one big bang or split it up into a series of little bangs. Just have a pool of points equal to your level in Invention (or maybe double that amount.) I would not allow Focused Invention to have more inventions though, no. I think you came up with something similar.
Good luck with it. In the end, OVA is what you make it!