In addition, the court may consider any other relevant factors.
A counterclaim under subdivision (b) must tend to diminish or defeat the opposing party’s claim, or it or the opposing claim must relate to payment of or security for the other, unless the person against whom recourse may be had is a party to the suit or the counterclaim has been assigned to the party asserting it; and if recovery on the counterclaim exceeds the opposing party’s claim, any excess recovered shall be held in trust for such person against whom there is a right of recourse.
Ind. R. Civ. P. 13