Pepelu's move to Valencia has left Levante fans furious.
The midfielder signed a ten-year contract last season, only for him to leave for local rivals VCF this week.
Valencia were able to prise away Pepelu thanks to a €5m buyout clause.
And in reaction, Levante have hung several banners around Turia critical of Pepelu.
One read, "Pepelu, traitor; you have not understood anything", and another stated, "Raised in Orriols, fled to Singapore".
Pepeu said at his presentation: "I don't feel like a traitor.
"I don't care about people's opinions, last year we all know the situation of the club. We signed something that we all hoped would happen, it didn't happen like that. And this year this possibility has arisen and all parties have come out winning."