I kinda wanna see Pulse's RHG battle but i doubt it'll top Terkoiz, no offence D:
If he used brush, it would've taken a long time, so i actually see the point in using line for bigger projects, but it kinda looked a little sketchy.
I personally prefer & suggest brush, because like what Pin said, it just looks significantly better in a sort of way.
Actually, with most animators, line is a actually longer to animate with, since brush covers with quick strokes that are easier to line up as for line youhave to position it correctly, also this anim was made with tons and tons of motion tweens making it a even longer process.