yes, the way Relentless works is, normally when a player tries to finish through contact, it drains their energy some. with Relentless it doesn't drain energy from the contact.
...now...if Lebron is going to the hole...he has Relentless, Bruiser, and Posterizer. if he makes a contact dunk...he won't lose any energy, the defender will have some energy drained, and Lebrun's teammates will get an energy boost. triple whammy.
also, this year Brick Wall depletes energy. so most of my bigs have Bruiser and Brick Wall, so when you run into that screen you get a double dose of energy sap.