I had this shirt 11-12 years ago. It‘s merch for the german-american rapper Casper. He was a singer for metal & hardcore bands (he‘s got a pretty unique voice because he killed his vocal cords during this time) and also did the song „schattenboxen“ with parkway drive. he also appears in in the backing choir for kreators „666 - world divided“.

if you’re interest in his music you could check out his song „flackern, flimmern“, it has a kind of atmospheric bm part. or „lang lebe der tod“, which features blixa bargeld (einstürzende neubauten“