[quote=ItsToppyTippers]
Pretty sure Lucy'd still have her magic; as long as the Tenrou Tree (the main source of her magic) is still standing back in her universe. Perhaps I could make her magic much more limited due to her being in a different area, and very much far from Fiore and Tenrou Island. Let's say her maximum amount of magic would be 175, and every time she uses a gold key, she would use about 30 of that amount, and every time she uses a silver key, she would use 5 of that amount since silver keys don't really use as much magic power. If she were open multiple gates such as two of her golden keys and keep them open for 30 minutes, every minute of keeping the gate open she can lose 1 of her magic ability. (2 gates= 60 magic, 30 minutes= 30 magic; 175-90= 85 magic left) And so on and so forth.In the manga, I've seen Lucy be able to open about 5 to 6 golden gates before she lost most of her magic. So I kinda cut her ability of opening gates to a half. Suggestions if you feel the need to?? ^^"
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Frankly, even if the world your character is from has multiple dimensions then I'm still in favor of this being so separated from the rest one's access to their native magic is cut.

Not to say we won't have it. But if OP gives a green light I might as well propose the valley have what's left of whoever was there leave behind some trinkets that act in a way as an access to someone's "native" magic. Whether that be locally borrowing someone's native rules (limited access to your tree, limited access to whatever dimension the Warhammer guy draws from) or giving them only this world's magic based on its rules until they manage to go home.

I'd leverage this on what I said earlier that in the case of many of these character's there are other parties - other characters or factions - with similar or counter-measures to that power written in; usually such a thing being the end-goal in mind for writing the story. And when you mesh them all into the same world in a clusterfuck fashion then it skewers whatever potential balance there was in the source material.

This is something to be weighed against the nature of technology based capabilities and magic based abilities. Or if the valley as a whole dampens everything not associated with someone's basic abilities (ie: if you're super human you're now regular human). But this would be unfair to our Transformer types (and difficult: how basic can a massive robot become when they're whole species' purpose is to turn into things?)