Use King of the Swamp depending on what you need. You can send it to the Graveyard to get Polymerization or use it as a Fusion Substitue. It's recommended to have more copies of this card and replace other Fusion Substitute monsters.
Here is my deck suggestion for people who don't have access for labyrinth builder nor dark paladin (like me)
u can use any fusion monster with 2k attack or more, preferably if u have a glossy/prismatic one, and u should try to get ur horus Lv8 out as fast as possible, if u manage to summon it the farm is guaranteed 100% as long as u don't mess up with the final secret pass/union combo, also u can get +8k with this deck