Carrying this massive heart was extremely hard as the bird monster found it to be extremely heavy even though it was perfectly fine carrying a little house and several people on its back without any problem. Actually even though this heart was definitely large, it was not that heavy. So this bird should be able to carry it without any problem but the bird was unable to do it.
As everyone was unable to understand why that was the case, Elena decided to explain the reason to them as it looked like no one here was going to discover the real reason. Actually as this heart belonged to a powerful ancient being, it released a pressure around itself that could make weaker people with low levels to get a debuff.