i learned it today on the 5th frenetic rip.
went to the 3 imps outside of nashmau. first i went blu/whm with a mnk/nin friend (thx kattekop ^^) the horn broke very often, but sometimes he did pop a new one before he had enough tp...
after the mnk left, i used my bf rdn char to swing his joyeuze. crit hit rate was not that good. the horn broke one time, when a smn friend (<3 eltimas ^^) came along. so i'm not sure what made the horn break. after frenetic rip, i launched a 300tp spirits within, to finish the imp. by that time we had blood aggro from 3 skeletons and had to zone to nashmau... running with red hp at night but with a new spell ^^.