Hi fellow SoulKeep Players!
This is my first PeakD post so forgive the formatting. Here is a quick guide for League 1 mission 4 using the freely given level 0 NFT's.
There is actually a pretty important lesson to learn here about how valuable spells are. They help with leaks and when placed properly can destroy a horde for only a few mana. In particular on this map, the largest hordes appear right away from the top left and left middle starting points and group up at that crossroads. Those spell placements are extremely important to succesful completion of this map.
Wave 1 - Upgraded Knife tower and Goo
Wave 2 - Add another knife tosser and card sharp, place Goo and Fireworks as shown
Wave 3 - Add a Charnel Pit, replace Goo and Fireworks
Wave 4 - Upgrade your Charnel Pit, add another knife tosser, add goo only
Wave 5 - Upgrade your top knife tosser, add a loom and knife tosser on the bottom, add firework only
Wave 6 - Upgrade your back line knife tosser, add fireworks only.
That should do it! Have fun, I will post the solution for 1-5 soon.