more tre shounen manga chapter covers!

some notes: 1. xu da's blade here is the dadao, or the big sabre. i swear this isn't a pun, it's different da characters. 2. the background is refencing a specific early 13th century painting, ma yuan's 'scholar viewing a waterfall'. (go look at the original, zoomed in, at the met museum site). 3. the abacus and the suanpan coexisted historically across the world from each other, but if one inspired the other is unclear (according to my shoddy research)