Are there any pedals out there for compression/sustian that would work good with metal? Do some compressions even suit specific genres or is compression just compression. Is it even used in metal music?

Thanks in advance
Yes, they are definitely used in Metal.

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compression is just compression. it's either going to level the string attack and add or sutract sustain or boost the string attack and add or subtract sustain. most metal pedals like the boss mt-2 for example has very compressed sound. other pedals like the metal muff has a slightly compressed sound. so yes metal music uses compression. it also works well as clean boost or lead boost or for funk. the mxr super compressor is a nice pedal.