WWE star David Otunga showed just how strong love is when he devoted himself to finding his niece a heart that she desperately needed to save her life.

Otunga tells us that his niece Kylee now has a brand new heart. He says the turnaround has been nothing sort of amazing -- Kylee is now walking and responding like she has fresh life breathed into her. It'll be a long road of recovery, but Otunga says Kylee is in great spirits and positive about getting better.

Up until last weekend, Kylee had been kept alive with the assistance of a machine and a continuous IV as she battled heart failure.

The star says Kylee's condition was rapidly deteriorating, so he hustled his hardest and attended tons of interviews to get his niece on the transplant list. Because her condition was so severe, once she made the list she was bumped to the top and received a transplant.

Otunga says they first got the news of a donor for Kylee while they were at Medieval Times for a birthday party.

As we previously reported, Otunga rented out a movie theater and had it sanitized so Kylee would be able to see "Boo 2! A Madea Halloween."

Once Kylee gets released from the hospital, we're told she will be living with her Uncle in his new home, which Otunga had bought to stay near the girl while she was hospitalized.