When you think about it, Steven has a ridiculously broken power set.

  • Superhuman strength, speed, and durability. Under certain circumstances his speed is enhanced even further.

  • Telepathy

  • Possession of others

  • Flight

  • Dream manipulation

  • Animating plant life

  • Healing/fixing anything - from gems, to human injuries, to broken objects, to removing chronic conditions like nearsightedness

  • Resurrection of the dead

  • Can summon a basically impenetrable shield that can be thrown as a weapon and change in size

  • Can create defensive bubbles around himself and others, which can be enhanced with spikes

  • Can create massive barriers that can be activated passively

  • Functionally immortal, as long as he still feels young/healthy

  • Can create shield walls that can be used offensively and defensively, which can be enhanced with spikes to...well, look what he did to Jasper.

  • Extremely gifted at fusion and has more fusions than probably any other character

  • Immune to gem destabilizing attacks

  • Can change his size and shape, modifying his physiology to make himself even stronger and faster, even the size of a monster.

  • Can generate an energy shockwave by shouting, which can destroy objects or disrupt things like Lapis' water clones or even disrupt fusions.

Did I miss any? Because this is a pretty big list. And keep in mind we never see Steven's full potential. We see a hint of it in 'fragments.' But considering he can turn into a literal Kaiju, if Steven ever trains to really harness his full capabilities he'd be pretty much unstoppable. Imagine a Steven who can transform into his monster form at will and maintain control of it?