Criatura — Bribón humano
2 / 1
Cuando sacrifiques una Pista, transforma al Investigador temerario.
Portador de verdades abrumadoras
Criatura — Hechicero humano
3 / 2
Destreza. (Siempre que lances un hechizo que no sea de criatura, esta criatura obtiene +1/+1 hasta el final del turno.)
Siempre que el Portador de verdades abrumadoras haga daño de combate a un jugador, investiga. (Pon en el campo de batalla una ficha de artefacto Pista incolora con "

, sacrificar este artefacto: Roba una carta".)
Clue is an artifact type. Even though it appears on some cards with other permanent types, it's never a creature type, a land type, or anything but an artifact type.
If Daring Sleuth's ability triggers multiple times before any of those abilities resolves, only the first one to resolve will cause it to transform.
If an effect refers to a Clue, it means any Clue artifact, not just a Clue artifact token. For example, you can sacrifice Wrench to pay for Alquist Proft, Master Sleuth's activated ability.
You can't sacrifice a Clue to pay multiple costs. For example, you can't sacrifice a Clue token to activate its own ability and also to activate Alquist Proft, Master Sleuth's ability.