His Guardian Bakugan was Aquos Preyas, who crashed Marucho's house party, which was thrown after he moved into Dan's town. Preyas was sent to the Doom Dimension in Marucho's battle with Klaus von Hertzonwhich made Marucho want Preyas back so much that when Klaus opened up his portal, Marucho followed him.
Later, when Klaus shows up with Preyas Dan and Runo find a way to get Preyas back by using the ability Pure Light. Preyas evolved into a two-sided Bakugan called Angelo and Diablo by coughing them up. Unlike the other Bakugan however, Preyas multiplies when he evolves, so Marucho got to keep the old Preyas. He multiplied into Angelo/Diablo Preyas. Preyas also has a move called "Change of Attribute" with which he can take advantage of the opponent’s gate card. When Marucho was being tested by Frosch he had to fight an old version of himself, the one who always listened to his parents. This sickened him but he was able to accept his past and how it made him who he is today and passes the test. When he brawled against Dan with Preyas and Angelo/Diablo Preyas he was ranked seventh. Preyas Angelo/Diablo are not in New Vestroia.
When he was in Vestroia he fought Aquos-Ventus hybrids Taygen and Hairadee alongside Shun. He originally just fought Taygen but then they teamed up when they realized that they were both able to use both Aquos and Ventus. He then defeated them by using a Diagonal Relationship with Ventus and Haos with Angelo andSkyress, and then a Pyrus and Darkus with Preyas and Diablo, defeating them. He later brawled against theTaygen once again alongside the JJ Dolls Jenny and Jewels and defeated it.