[QUOTE=King Dong;29452 What do you purpose I should do for a second MR tank? [/QUOTE]

You do not need a second MR tank. There are a few guides that use 2 soldiers for UP generation (Katie and Phyllis), like key kii's and there's also this one that uses bandits to slow the liches.
Remember, you only need to do the 500 kills once, after that you can go with 491 ones to grind the 10000 total kills.