I found a solution for bloodling in soulkeep

In Soulkeep every fiend has its own features that need a specific deal with it and this is your strategic role in the battle to find what every bloodling could do in the battle as a single one and then you could put a plan for a group of fiends that comes to your gate.

For me Bloodlings is a very dangerous fiends and although it didn't have armor or any defensive style like attacking towers and their HP is low as it is only 200 but these ones are extremely fast with speed of 125 and there are annoying thing about them also that they come in large numbers and groups.

Best Solution for them is not buying towers as epic or rare from the market but the solution with a common tower that are with you in the battle and this one is Gloom Owl that are the first tower that you have used in the battle and in first level.

Gloom Owl is best Solution for Bloodling but with some conditions to eliminate them all and first one is to be upgraded and second one is add two towers of Upgraded Gloom Owl close to each others and in this case those bloodling would fall in the trap and no one could pass from them.