Katsu, the Wanderer

The first time an attack action card you control hits each turn, you may discard a card with cost 0. If you do, search your deck for a card with combo, banish it, then shuffle. You may play it this turn.

Rulings

From the Crucible of War release notes

Katsu card text has been updated in Crucible of War. It is a non-functional change.
You may elect not to banish a card when searching, however you still must shuffle your deck.
Katsu’s hero card effect triggers only the first time you hit with an attack action card each turn. If you choose not to resolve the effect and you hit again later in the same turn, Katsu’s hero card effect will not trigger again.
The card remains in the banished zone face up if it is not played.
A card without a printed cost is not a card with cost 0.

From the Welcome to Rathe release notes

You may elect not to banish a card when searching, however you still must shuffle your deck.
Katsu’s hero card effect triggers only once per turn, the first time you hit with an attack action card. If you choose not to resolve the effect and you hit again later in the same turn, Katsu’s hero card effect will not trigger again.

ClassNinja

TypeHero

Life40

Intellect4