Hey, sorry about the delay. It took a full day to get things right, but i ended up getting a shiny female Deino in about 4 tries on my second attempt (my first, i didn't have my SID in, so I kept catching the right one, but it wasn't ever shiny). An hour later, I caught a second one for my friend, who was over at the time.
Teaching him to RNG now. Thanks again for the help.