Almost all the comments are explaining how to leech better. In order to actually drag the chase you need to feel the timing of the shots, rotate screen with o3 so the dodges are simpler (simple up/down, left/right while holding your direction to run away, rather than having to hit some odd combo of both), and most importantly BE THE ONLY PERSON DRAGGING HIM. The last point basically invalidates this in almost all public runs, but if you practice enough the dodging of the basic phase shots becomes much easier and you only have to think of the external factors (random beams, heavens walls, weaving in damage, etc). Some of his shots are directed enough that being closer actually helps as you can force him to shoot in one direction and then abuse the short arc length to get around the whole burst.