you mean, if we make it so that whosoever manages to store this inverted gets the points, then you can transfer and try get it back next untap, and opponent can then stay and get it back your next untap, and so forth...you wouldn't get kill points I suppose since the attack takes place during untap, unless we specify it. How can we make clear who is opponent in this sequence?
Locked in battle until every sane person (>6 mind) has fled!
would mean a bit different mechanism though.
Weapon. Warrior only: +1 prowess (+2 against Elves). Tap a covert diplomat during any player’s site phase to transfer Usriev (invert this card) to a character in opponent’s company at the same site with a mind <6. If Usriev is inverted, it cannot be normally transferred again, and each untap phase bearer is attacked by another non-Hobbit character with a mind <6 at the same site (opponent's choice): if bearer becomes wounded, attacker takes control of Usriev, and if bearer is eliminated, place him in opponent's mp pile. Only one inverted Usriev may be in play per player. Usriev gives the holder of this card 3 MPs if inverted.