Powerball winner Edwin Castro purchased a highly sought-after Malibu mansion for nearly $4 million under a mystery LLC after making history with his lotto ticket, RadarOnline.com has learned. Castro was spotted in the garage at the three-bedroom, two-bathroom home, sipping on what appeared to be a boba drink while having a chat. The home is on the PCH highway and came fully furnished, per its listing. An eyewitness said he let himself into the stunning abode. Property documents revealed it was purchased in 2023 under a mystery LLC, the name of which is the home’s address. Filings from the Reco…