No Heart Lost Towers in Soulkeep

I have found good formation for level 5 in soulkeep so you can not lose any heart in first waves before new fiends came and as this is the hardest level and last level of league 1 so you can use it in any level before that and it will work at least in first waves until you gather some mana to upgrade them or add new towers.

First tower to be used and it is the most important one of them is Fountain of Terror and it is amazing as it is the essential one to defend against fiends in two ways as I didn't see such a tower with higher range than Fountain of Terror so it is first tower to be in your formation.

Second Tower to be with you is Gloom Owl and as it is a physical tower with some damage that could reach more than 60 so you can use it and in fact I am using it since first wave when I start the game with with it then I keep it in my formation.

Third tower to be with you is a magical tower that can hit with magic attack and high hitting power and it is also fast so you solve the problem of armor with fiends and also fiends with high speed and it will be your magic weapon in this formation.

Last tower to be used is Charnel pit and as it is the fastest tower in the game so it will help also in this formation to be completely good to pass some waves without losing any hearts and this what I have done and then you may upgrade them to pass final waves.

For Spells you can use Venus Fiendtrap as it is the most important spell and I often put it close to the gate to kill 5 Fiends who try to enter the gate and raining cat also before it and if you are in level 5 and unlocked third spell you are free to use Cheapo, Gear Grease or Stew of Doom.