Regigigis is like the worst legendary, but it can be an absolutely insane Pokemon. It's got some wild legendary, fitting stats and it's actually pretty scary with its base 160 attack and 100 speed. The problem, it has the worst ability in the game. Slow start makes it so that for the first 5 turns it's in, its attack and speed are cut in half. It's damn near impossible to make this thing work, but it can get a little bit of help from its solid HP and defensive bulk. I like to run stab body slam for a chance to get a parra, which makes Regigis live a little easier and wasting slow start turns with a little bit of luck. And with Drain Punch and Leftovers recovery, we can grab some much needed health to stall as long as possible and even use rest to heal ourselves to full. We pair that with Sleep Talk to try to get attacks off while we're asleep, and with Slow Start wears off, it's time to unleash its full power. Regigigis might not be very good, but it's actually kinda fun to try to get him going.