The pattern is always different. Go to the gypsy where you started the quest. She will tell you the code again. I suggest writing it down.
Chat with our AI personalities
I would say you should be level 50+. You could be lower but with better food.
A quest walkthrough for Demon Slayer can be found here: www.runescape.wikia.com/wiki/Demon Slayer
If this is part of the Demon Slayer quest, then the link below should direct you to your answer.
look on runehq
Take them to Xena and she will give u Gp for them