I know many can find them frustrating, but experienced gamers and Halo veterans may come to enjoy Legendary Difficulty. I found some Legendary Campaigns unrealistic and immersion-breaking, but thoroughly enjoyed Halo 3: ODST's Legendary Campaign. It was my favorite one (followed by Halo 3's), since enemies' shields weren't ridiculously powerful (or AS powerful) and I didn't have to be totally reliant on the Plasma Pistol EMP and Headshot combo.