when you get in Str, Dex and Con will instantly become 20 and plus 5 for all rolls (except damage} and damage will be doubled, and movement speed is tripled but all smaller weapons will become unusable also you will be able to do 1 more action per turn

only can be used once every long rest 

adds 50hp to you, if you lose the 50 it will explode you must make Dex save to get out of the mech if you fail you lose half your health