How to get a Killionaire

In Halo 3 for the XBOX360, there is a medal you can achieve called a Killionaire. To acheive a Killionaire, you must kill 10 opponents within four seconds of eachother. I currently have four Killionaire medals, three from Grifball and one from Zombies. I have found that Killionaires are easiest to obtain in Grifball since the spawn points are so predictable and spawn times are quicker than normal gameplay, hence more enemies to kill within four seconds of eachother. Below is a video of my third Killionaire in Grifball.

"Killionaire #3" by RedLace : Watch it on YouTube