If your thinking you'll be ok with a majano anemone, then you read the wrong sites lol. Majanos can spread like wildfire and will eventually take over your tank, whether or not it's reef.
I can't say for sure if it is a majano or not, as it's rather hard to see on my phone, but if that's wat you think it is, you need to get rid of it ASAP! Some Aiptasia-X works rather well and its not real hard on the wallet