Simplify the following text for a Grade 6 native English-speaking person.
Original: With the release of UFC Undisputed 2010 Lesnar became the first man to appear on the cover of a WWE and UFC video game as he was the cover star on Here Comes the Pain .
Simplified: Brock Lesnar is a former professional wrestler for the WWE and is now with the UFC . He was the WWE Undisputed Champion .