After the assassination attempt on the Ghost Ship, Sato's desire to reach Ecruteak City as soon as possible grew even stronger.
Haunter's talent had always been just a little weaker than Zoroark's. On top of that, Sato had never stopped Blood Feeding Zoroark, and his mastery of the Dark Type far exceeded his understanding of the Ghost-type.
With all these factors combined, the gap between Haunter and Zoroark would likely keep getting bigger and bigger. But Haunter had always been dependable at Crucial Moments, and their coordination had grown increasingly seamless. Sato could not possibly give it up.
Ecruteak Gym in Ecruteak City specialized in the Ghost-type, but no one would teach their skills to an unrelated stranger for no reason. A letter of recommendation could only be adding brocade to flowers. Sato's experience from two lifetimes told him that he himself was the most reliable one.
Therefore, on the way to Ecruteak City, Sato needed to prepare some additional bargaining chips.
For example, a highly talented Ghost-type Pokemon, or the as-yet undiscovered method for evolving Dusclops into Dusknoir.
The key evolution item was the Reaper Cloth. It had indeed appeared several times in Sato's memories, but none of those instances were in the Johto Region, and the time had not yet come.
That left highly talented Ghost-type Pokemon as the only reliable option. For that reason, Sato deliberately took a detour and arrived at the Johto Region's famous Pokemon graveyard, Death Monument Valley.
Unlike Lavender Town, which was famous in the Kanto Region, Death Monument Valley in the Johto Region buried many Pokemon as well, but it was actually a mass burial ground left behind after a war a century ago.
Resentment, ghosts, and all manner of supernatural things filled the place. Naturally, there were quite a few Ghost-type