Yep, unfortunately that code OuricoDoido is presenting a tutorial on is lifted straight from Megamix. He condensed it to make it look like he coded it himself, but quite a few people have confirmed that it is indeed stolen. If you see anything related to ASMtoSegaGenesis, it's definitely something you should run away from really fast. If you're looking to code it for yourself, Markey's conceptual information is probably the best guide to start off of. If I were you, I'd check out the game's code to see how calcsine and calcangle are used in context. I created a homing attack of my own a while back and did so after looking into how calcsine and calcangle worked, figuring out how to load a given object in object RAM to a register and figuring out how to determine information about that particular object.