Applebloom finds a strange glowing rock after doing her chores, after she picks up the rock, she gains the Powers of the Sea God Poseidon, meaning she can now Control water, however Applebloom can now hear the sea god's voice in her head, since Applebloom has also unknowingly absorbed the God's soul as well.

Also, Applebloom has gained a Cutie-mark of a Raindrop
Course with Applebloom's new power to control water is noticed by Twilight and rest of the Mane 6

Human Tag: In this case its case the human is the soul of Poseidon