http://www.byond.com/games/Enigmaster2002/IconUltima
(Contains tons of icons from other sources, now this normally can slide because they are uploaded by other players, but the base world map does contain RPG Maker graphics.)
All graphics released with the game were either made by volunteers or found in free icon packs on this site. Whether or not the ones in free icon packs were stolen or not is up to speculation.
Considering I have no knowledge of what the RPG Maker graphics look like, as we're going back twelve or so years since I last looked at the software, please provide a list of which tiles come from it and we'll see what we can do to fix it.
Ignoring the legal issue there's still the issue of quality. Most of the games that feature RPG Maker graphics aren't that good. It's also an art style that's often seen. If BYOND had 100 different, high quality card games it'd be difficult for you to make a card game that gets featured - it wouldn't be because the game is bad but because it's been seen before. It just isn't feature worthy. Ripped graphics act the same way. If you ripped graphics from a very obscure game and nobody knew they were ripped, they wouldn't think any less of your game. If you used a commonly-seen tileset people would judge your game.