You are now Shepard, the galaxy’s greatest hero, the one who defeated the very Reapers themselves. Or at least you have all of their skills, knowledge, and powers. Depending on the version of Shepard, they can be the galaxy’s finest soldier, its greatest engineer, or it’s most powerful biotic. You are all three, gaining the benefits of all three classes, and their mixed classes and specializations, perfectly mixed together and their benefits stacking on top of each other. You are the perfect N7 operative.
Your biotics do not rely on an implant, they now operate similar to an Asari’s innate biotic ability, and your biotics are incredibly powerful, capable of tearing through a dreadnought, and extremely precise, allowing you to use it to brush your teeth if you want. Your use of this ability is as instinctive as your heart beating, requiring no effort on your part and can grow stronger over time. You also somehow possess the ability and knowledge to create Element Zero through your biotics.
You are also given a unique and powerful Omnitool, capable of performing almost any function and that never runs out of power or resources. In the event it breaks you’ll find it repaired the next time you need it.
And finally, you gain Shepard’s ability to somehow seamlessly encounter and integrate powerful new companions into your crew. If you desire it, it won’t be long before you’ll have a powerful, interesting, and perfectly loyal crew following your command.