Board Thread:Questions and Answers/@comment-29700757-20180723150949

Before this upgrade is called Soulbind and gives you lives and sacrifices a tower if a bloon leaks. Now it can spawn undead MOABs and BFBs and is now more expensive. So... is this new upgrade better?

p.s. they maybe just've been replaced it because the soulbind is cringy lol 