I know that if you use Fusion Bolt and then Fusion Flare, Fusion Flare gets powered up and vice versa. But if you use Fusion Bolt for example and then your enemy uses Fusion Flare and vice versa, would his be powered up?
Yes, you're enemy's Fusion Flare will be powered up. Unless it's in the same turn. If it is, it has 100. If it isn't, it's 200.
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Yes,it would be powered up.