If you don’t control a blue or red permanent as Wandering Champion’s ability resolves, you can’t discard and draw a card. The blue or red permanent you control as the ability resolves doesn’t have to be one you controlled as the ability triggered.

Wandering Champion’s ability doesn’t trigger if you don’t control a blue or red permanent immediately after it deals combat damage to a player.

If the only blue or red permanent you control is a creature that’s dealt lethal damage at the same time as Wandering Champion deals combat damage, Wandering Champion’s ability triggers.