Cheapo and Gear Grease for Charnel Pit
Soulkeep towers with high Mana should have a good strategy to be used as the more you save mana in the battle the more you be able to use more spells and towers in last waves and also more spells in the battle and this would make towers mission in eliminating fiends.
Charnel Pit is considered one of most common towers that has been used in battles and by most players as it has a very good features like Speed which is the main feature of charnel pit which its fire interval of 0.6 and also its range is reasonably good and also physical damage is good.
But the main drawback of charnel pit in low levels is that it can be used with 120 Mana and this is so high for starting the level with this tower so this is a trick that I have used to be able to add a charnel pit in the battle and get most of it and this would be with some spells that I cand use with also some towers.
Cheapo would decrease the mana cos of charnel pit to 84 and this would save about 35 mana and if we considered cheapo cost which is 5 mana, this would makes you save up to 30 Mana and hence you could start the level with charnel pit like any other common towers that are cheap.
Gear Grease is also amazing in assisting towers and one like charnel pits don't need a Spell like it but using Gear Grease would make it more amazing and its speed may be less than half second and this would make it like a machine gun literally and no fiend could stop it from attacking and save you some hearts as you would need them at the last wave where all fierce fiends come.