Kero: The Boss Variant (2018)

Apply the boss sticker at the back of both their respective tokens (1 for each clan).

Those tokens now play like any other explorer tokens but have an ability that can be triggered once per game:

In case of a tie, the boss power can be activated to win the territory on which it is located. If both bosses are activated on the same card, no one wins.

Promo found in Plato Magazine 109.