Of course. Far as I can tell in terms of places that Chacu Challhua likely entered to place marks--

I need to at least be capable of maneuvering underwater to manually locate and remove any markings I may find, but also to go down into deeper depths on land than would generally be recommended. I've at least half-certain that he also used me to climb the volcano that's on the Duel Academy island, in order to place at least one or two markings there, as well.

Or at least that's what I've been able to piece together from the rare times that Tezaki is talkative, towards me.