Virtue - prudence, justice and fortitude are certainly there. (Temperance too if you consider the other two headings.)
"I thought, 'I've set this bloody thing off and I'm going to do whatever it takes to protect the others."Guts - he did not hesitate to jump on the grenade to save his three fellow Royal Marines and said that he expected to lose a limb but hoped to keep his head and torso intact.
Brains - he rolled over to use his backpack to shield his body from the shrapnel fragments.
Fortunately, the backpack that the Royal Marines carry has quite a lot of kit in it. His had a lithium battery, a medical kit and a 66mm Rocket. Thanks be to God, he got thrown up in the air and suffered only a nose bleed. Within an hour, he was back fighting the Taliban and shot an insurgent approaching their position.
L/Cpl Croucher has kept the backpack as a souvenir. Now that's something to show your grandchildren! Along with the medal of course.