The best thing you can do for your tower run is to build up that thunder grid as much as possible. You'll need 6 teams of three and the lower levels can be done with just a strong soul and grid. Plan to use thunder Rs and SRs as much as possible and then collapse you thunder himes into a couple of strong teams as the levels get harder and bring in off element teams to keep pushing.
Please note: You don't have to complete the tower, you just have to beat the other players for a higher reward.
Good luck may the odds be ever in your favour.
Dejnov.