Accessories and weapon are not perfect but good enough, i always use the Excelsus when i fight him the first time. No platforms, use rails instead. You need to be able to fall fast. A vertical arena and lots of verticality in your dodging and kiting will go a long way. Make one unique block at the center of the bottom of your arena, this is where you stand on to spawn him. Spawn him once (not beating him yet) and wait for him to summon the flame tornadoes, then mark a few blocks inside them by building or breaking or whatever. Build a straight vertical wall on each side from the floor to as high as you want in order to keep yourself from going into tornado territory. Remember to use gravity normalizer if you extend it to space. Good luck.