Illusionary Marucho is an illusion of Marucho created by Frosch, one of the Legendary Soldiers. He only appeared in the Bakugan Battle Brawlers episode, I am Marucho, Hear Me Roar. He appears to be a younger Marucho.
When Marucho and Preyas landed in the Doom Dimension's trials, when Frosch and Marucho were battling for Marucho to pass his test, Frosch created Illusionary Marucho for Marucho to face up against. It was quite surprising for Marucho to battle his younger self. Later on the battle, Marucho's Preyas duplicated himself into Angelo/Diablo Preyas. Marucho won the battle against him. This Marucho was Marucho before he discovered Bakugan he always did what his parents told him and was not very independent.
Like Marucho, he seems very smart, except that he is much younger than Marucho. He is also very complimenting.