I actually beat Vaati the first time, but I did know what to do... I peeked at the ZD guide!! But I beat him with 2 red potions and fairy, with 18 heart containers. Or however many it is if you're missing two.... I didn't count. Out of all the final bosses I've faced, easiest was OoT Ganon, then WW Ganon, TP Ganondorf, and PH Bellum and ST Malladus... The DS bosses were hardest to me because I couldn't figure out the controls at first!! It seriously took me close to two hours and dozens of tears before I could figure out drawing-the-hourglass-thing in PH!! XD And I thought the Malladus battle was just too long and drawn out.