The Fallen is immensely powerful. He commands mystic, entropic arts, and when at full strength he can un-make creation at his focused will. He is rarely defeated; at best he is contained, where he waits with eternal patience for the chance to unleash his dark powers once again. Though he has at times been imprisoned between dimensions, this rarely lasts. When his power is at its height The Fallen can open space bridges and travel between dimensions and realities at will.
If there is any reprieve, it is that there is only one of him. Like his brothers, The Fallen is a multiversal singularity, meaning that in all of the vast multiverse, he has no alternate-universe doppelganger. He may appear different in different realities but that is merely surface, it is always the same singular force of eldritch evil beneath. In several realities he is the originator of the Decepticons, the catalyst that prompted Megatron to claim power for himself rather than the greater good. While the exact details of his past are complicated beyond the understanding of mortals, two things remain consistent: He is bad news, and he's on fire.