It's a 26 episode series. First season was 13 episode (1 joke episode, 12 real ones, one of the real ones was japan only)
The tower doesn't have the blue crystal rod, gilgamesh has it, in his castle. He's tricked neeba and is using kaayla to end the curse that's keeping him alive over the past 100+ years. Ki, gilgamesh's girlfriend/wife is trapped in the tower. Gilgamesh IS "druaga" because of the curse. Ki (the red ghost) was kidnapped by the cursed half of gilgamesh who then created the new tower. Kaaya is their granddaughter and is following some sort of plan.