I used a water/ nature deck. Lots of water blockers, and a couple of crystal lancers mixed with the easy creatures and evolutions of the nature kind, namely barkwhip the smasher, leaping tornado horn is just as good as it's evolution Nofea horned protector... I basically used the basic forms that evolve into barkwhip and those annoying tornado horns. If you don't want to use barkwhip, or you just want more diversity, use the other evolution of his basic form instead. Also, ELF- X was a life saver. I didn't really use any spells.

I found a water/light deck works very well. Get a lot of low mana water creatures (blockers work VERY well for this), and build up an army. Make sure you have plenty of the light card, Diamond Cutter, and use it. All of your creatures will be able to attack. Crystal Lancers comes in handy as well.

I won useing a darkness deck. Just use a good deck and winning the first duel helps. Just having a deck that is mixed or not is good.

a pure light deck really helps against mimi cuz u will notice she keep summoning dat irritating barkwhip.....-_-...add lots of blockers...especially ladia bale,gran gure...n include low lvl blockers as well...lots of it...don bother 2 include offensive cards inside..i tried n got slaughtered...pure defence...den when the time is rite...use diamond cutter...in de event that this event backfires...keep toel in ur field....i also recomen including high lvl attackers like alcadeas,hanusa,miar..don bother with low lvled ones....2 noobish...XD...any questions ask me ..

i have beaten mimi with a water and fire deck blockers of water and speed attackers of
fire this is the deck which you can beat mimi easily

i suggest making a deck full of blockers and with some diamond cutters a spell card that
allows anything to attack the enemy even blockers with R

i used the lvl 3 nature deck i got from inputting forest in my player's name....
and its full of barkwhip,the smasher,maybe 4...
they're best in short time evo-summons,paired with steel smashers and burning manes!!!
just keep summoning direct attackers(Torcon or Bronze-arm tribe will do,as for every time
barkwhip attacks,each beast folk attack raises to 2000!)also you can keep on summoning
until you get the trump card fighter dual fang,coz its a double breaker...
and with a mix of darkness cards like terror
pit,death smoke and the nature cards like natural snare and mana nexus,you'll sure to
bring her down...same with the others(mikuni,hakuoh,kokujo)but not with george,as you will
have to fight him with more blockers and an unblockable evo-double breaker,which you will
find in the sogville's deck...The sogville's water deck,which costs 300 credits..quite
expensive but worth the shot,,,,,,,,,,...
oh,and by the way,i have just finished the game......hahaha