On the topic of lyrics:
DragonForce are Power Metal. They don't have to sing shit that makes sense. They just pencil down a load of shit about epic battles and fighting and fire and stuff and make it rhyme/fit into a time signature.
Such is the beauty of Power Metal.
On DragonForce VS Metallica:
How the hell did we start talking about this? They're nowhere near similar. Bar the fact that both Hammett and Li are borderline-virtuosos, but fall just short of the mark for some reason.
Metallica are Thrash Metal/Traditional Metal/Hard Rock
DragonForce are Technical Power Metal
Not really a lot to compare.