One thing that can be really annoying (apart from constantly dying to the Solar Pillar) is not knowing how far you even are to completing a pillar. The wiki does show you how many enemies you need to kill for the barrier to go down but I think a Counter above the Pillar maybe could show you how many more enemies you need to kill. For example if you're playing on Normal, the counter would show 100 and every time you kill an enemy, it goes down until it gets to 0 in which the barrier goes down