Well muken would be fine if it lasted as suggested for 5 rounds only or the boost didnt work in void. In my opinion thats probably the best suggestion (those 5 rounds). Big spenders will survive 5 rounds and still do nice damage and be on top. The rest of us plebs who can survive only one round will at least still manage to do some damage if our muken has good enough base attack and have something to boost attack further like hiki, kyoka or formation bonus. Banning muken or something of that sort would only harm the weak players and did almost nothing for big spenders the same way the def buff did. Big spenders still doing billions of damage and most people dropped to 600 dmg unless they use the trick with burn/poison debuffs.