I have being trying to get polearm material from many weeks but boss do not drop Why. It's not just polearm but other weapons material too. Don't disappoint after trying so hard. Tips: make treasure opening animation. And make twist in game where all character loss power and have to complete mission to get back his/her power or an island with zero magic or anti magic. Where you are totally dependent on your playing skills. Waiting to see something new. Where players feel challenge.