I had played around 10 flushes. I basically had to get a bunch of copies of a single rank of card, then I played every hand type I could. The secret is to always avoid playing pairs and high cards, because if you play those too often you'll max out on the hands you want to use as discards. Eventually, I had several copies of an 8 card so I was consistently drawing 3oak, 4oak, 5oak and flush of a kind, which allowed me to play each of those in moderation so I simply kept powering up the obelisk across the course of the run.