Relevant Text: http://rules.l5r.com/Costs_and_restrict ... nd_changes Costs must be payable when an action is announced under the Good Faith Rule. If, due to interference from other effects, a mandatory cost cannot be paid at the point when it must be paid:
No remaining costs need be paid, but costs already paid are not refunded. No effects of the action or trait resolve, and the ability or trait is considered to have been “used.” If the cost was for a card to enter play, it is discarded.
Dirty Politics: 0 GC, 1 FV Political Reaction: Before another player loses Honor: Negate the loss, then gain Honor equal to the amount you negated
So the situation is this. A Corrupt Crab decides to bring random Oni A into play, who carries a 3 honor loss entering play cost(As honor loss is a cost to bringing them into play as I understand it). I Dirty Politics the 3 Honor loss, Gain 3 honor, and the cost is no longer paid so the Oni is discarded, right?