I've gotten it twice, and know others that have as well. Everyone I know got it from Smasho/Foulberto - I had to wait a day or so till I mastered dagger before I could use mine. It's ok - but I like my swords, guns and dolls better.
its all about luck,. i had 7 lvl 50 and only Rhys had legendary item,. and its double, 2 Elpatron and 2 Silver Freeze. But,. i got some theory,. make u skill like what weapon had,. so far i think its works. as example ; for El Patron, its had sweep skill +3.. so fill on sweep at least 1..