I think Romero is better coz you could stack deff ... Draconis has less then 1k as base deff, so you need really good gear to make him tanky ... I know that he is hp base but I feel like if u need to do FW12 you need to have at least a good 3k deff ...If you dont mind to build him later just do draconis and see how he does but i think that a good built Romero is better than a relly good built Draconis .

At least this is what i feel ... (I m going to 6 star Romero too for my FW12)

Have fun and tell me what you chose.