In my opinion, Ghost-Petal moves are somewhat better than the Dancing Demon ones. If I remember correctly, Dancing Demon only hits multiple enemies standing infront of your swing. Ghost-Petal, on the other hand, swings a full 360 degrees, and it hits 5 targets at a time, as opposed to Dancing Demon's limit of just 3.
From my experience, one combo in particular is extremely effective for spear/glaive users. I learned this from Demarthl: Approach target, imbue weapon with your preferred magic skill, and then use Soul-Spear followed by either Ghost Petal or Chain-spear Tiger. Using this, me and Dem are able to destroy mobs equal to our level in just those two hits (and without the aid of Draft).
Of course, we are both almost fully Int characters, so results will obviously vary depending on your character build.
Hope this helps.
