another old puzzle! here’s one i made for logic showcase 49, all about clues whose meanings change according to certain conditions. i took the opportunity to make a castle masyu, one of my fav masyu variants despite its rarity, and in particular i challenged myself to make an antisymmetric one w/ no clues at the edges of the grid. i quite like this construction, which happened to place dead last 
castle masyu rules
draw a loop that travels through cells orthogonally and does not overlap itself. for each black circled cell the loop visits, the loop turns at it and does not turn at the previous cell and next cell. for each white circled cell the loop visits, the loop does not turn at it and does turn at the previous cell and/or next cell. each unvisited black circled cell is outside of the loop, and each unvisited white circled cell is inside of the loop.
“complete with moat”