Easter Egg from the Rebels next episode teaser : Dark Side Secrets - Visions and Voices

We see something that looks a temple of Dathomir that his Maul's lair. 

There are really many things there like a picture of Duchess Satin on the wall, the Dark Saber, some battle droids heads, Mandalorians helmets from the Shadow Collective but what I found really cool is the bloody letter writting on the wall:

I translated from Mandalorian Alphabet : KENOBI. With he face of Maul and the finger pointed that looks Awesome!

maul knows that Kenobi leaves and he will hunt him !