When exactly do you play effects with "response: After you win/lose a challenge"?

After the challenge has ended, or directly after the winner has been determined and before claim i paid?

Believeinthis said:

All responses (except save/cancel) are played at the end of the action window as always:

1. Determine winner of challenge
2. Challenge result is implemented
3. Reward for unopposed challenge is awarded
4. Renown is awarded

5. Passives (for example deadly)

6. Responses

On a similar note, what is considered "during" a challenge, such as with Tears of Lys? Is it considered "during" up until the final responses are played, or is it over once the winner is determined?

Mantaeus said:

Yes.

Rogue30 said:

So if KotS Brienne is participating, opponents can't play thing like blood for blood and red vengeance?

Believeinthis said:

Correct.