Hello!
For Defection, you started well by making Tentacles joining you. However, after that, you clearly did it the wrong way. At first, you don't have to fight hornies, you must avoid them get in your dungeon. You can achieve this by reinforcing the walls quickly when you dig your way through the path of earth. Then, leading the heroes killing the blue keeper is the second mistake. You must keep the creatures of the blue keeper alive since it will become your main army. There's also a huge flaw in the design of the level where you can already move and get to the main hero base. This has been fixed and will be included in a future version of KeeperFX.
So, briefly, what you have to do is to capture and convert ALL the enemies you encounter so that, when you have them all so that you get an army of over 50 minions, doubled with Multiply bonus, you'll use this army to beat the final heroes in their main base. First, You must claim the prison which isn't hard at all to do. Simply, after you dug through the earth path that crosses the lava I mentioned earlier, you must AVOID to open a path to the white door at the West of your dungeon. Instead, dig North along the wall and keeps following it until you reach another door up there. Break that door and start claiming everything. Do not free the heroes yet. The prison is to the West right at the corner, through earth. Now, a prison is good, but how about being able to torture and convert the enemies? You need a Torture Chamber and the only Keeper who owns them is the Blue Keeper at the wide area at the North. Simply get a way to reach the Torture Chambers using your imps and tentacles. Hint:
Spoiler
notice that the Blue Keeper doesn't have any imps. Also, check your spells.
After that, the rest should be easier for you. Start with the small hero base, capture and convert. Once empty, claim. Avoid boulders. You'll discover the temple and the Multiply bonus. Sacrifice for better creatures.
The trickiest part is to capture and convert the blue creatures. A few hints for you:
Spoiler
1. Be sure to capture them after they eat to avoid them dying of hunger.
2. To avoid the creatures to be picked up when near death, they must have no lairs.
3. If you decide to attack creatures, don't leave them alive: capture them. Otherwise, they may become angry for not being able to rest and start destroying their dungeon or kill friendly creatures, which is a thing you want to avoid.
Finally, only the hornies remain. You better get them for last since they get angrier over time. Once all captured, you should have enough minions to defeat the main hero base. They have an enormous army so be prepared! Good luck!