I had the hardest time with spear break until I came across this program.Final Fantasy X-2 Ultimate Sphere Break FAQ - IGN FAQs
Inside this guide you'll find some links to copy and paste to your address bar. The middle one is the best as it's designed for 3 coin combos. Which is ideal I found putting it in practice. The author came to the same conclusion I did. Anyway, with this program on your computer it makes that evil Shinra so much easier. It tells you the best moves to make. I did it in 1 attempt. With turns to spare. This may already have been posted on this site, but I havn't seen it. So I'll give it its own tread and hopefully it will come in searches for people looking for help with spear break. Thank the author.