Ewall had one reply, "SCREW YOU OLD MAN!" The engines revved loudly as he peeled out driving like a madman toward the battle. His battle brothers rushed by his sides, some driving around the Dominatrix as... somehow they knew what he wanted to do.
A chant began to rise over the shortwave vox... "Ewall... Ewall... Ewall..." it began slowly and built up to a furious scream with yells of 'YOU CAN DO IT!', 'VICTORY IS YOURS BROTHER!', and 'DRIVE KNIFEFALL, DRIVE!!!!'. He pulled hard on his bike as the spikes on the wheels dug into the carapace of the huge Tyrannid. To Ewall the world we silent as his bike jumped off the back of the Dominatrix and he could hear the chanting in the background.
He pulled out the Grenade, he knew if he stuck this landing it was going to be a lot more than some scraped knees or a bump on his skull. But he was Ewall Knifefall... and this was his home. He grinned madly behind his helmet as he yelled out his witty quip, "SPECIAL DELIVERY!" And he threw the grenade.
The Tyrannids lost their minds with the death of their Queen and it was a Victory for the Imperium of man! However... they could not find Brother Knifefall. Vortex Grenades being so unpredictable... just like Brother Knifefall. They spent three days cleaning up the Tyrannid mess and were prepared to mourn their fallen Brother, his clan had arrived to pay their respects as well having seen and fought alongside the Marines it was only right that they should mourn the loss of one of their own...
A loud rev made everyone turn their heads as a bike that looked like it was barely holding together drove toward them. As they got closer and they could see through the dust... they saw the bandana around his mouthguard... it was Brother Knifefall... so a funeral turned into a celebration.
(Notes: Cape could also be his clans colors but I'm figuring those would be the colors for the 7th company. Like Look at old daredevil clothes for that type of gawdy)