If your version was 3.1U, U need to update to a game that contain 3.2U firmware. MK will be useless, since there`s only PAL version til now, and it contains 3.1E_v2 version. Even if you have a NTSC-U version, it will only unbrick if you never made the SMG, Wii Chess or SSBB updates or a "version" firmware.
Okami will only unbrick if you never made updates from those games: Aftermath, Worms : A Space Oddity, Opoona and Okami. If u never played this games, then you can make the updates from those games and it will unbrick your Wii (NTSC-U GAMES ONLY!). If u did some update from these games, the update wont work, and you need to try this:
1- If you never made those (SMG, WII Chess, SSBB) updates, try it ( WITH A NTSC-U VERSION!)
2- If you never played:
Battalion Wars 2 (or)
Pokemon Battle Revolution
Donkey Kong: Barrel Blast
Mario Strikers Charged
Big Brain Academy: Wii Degree
FIRE EMBLEM 10 USA
Mario Strikers Charged
SPORTS PACK for REVOLUTION
Try to update from any from any those games.
3- If you never played:
LINKS CROSSBOW TRAINING (or)
Guitar Hero 3
ENDLESS OCEAN
Try to update from any of those games.
4- If you never played MAJOR LEAGUE BASEBALL 2K8, try this update.
5- If you never played Mario Party 8, try this update
6- If you never played Super Paper Mario, try this update
Any of those choices will work.
Edit: AND REMEMBER: ALL THOSE GAMES ON THE LIST NEEDS TO BE NTSC-U!!!!