At super high energy, Strong Force becomes weak to act like Electroweak Force (Grand Unification Theory; hand-waving version 2.2). Well, I am NOT trying to find Theory of Everything with this hand-waving question. I am just curious how Gravity behaves at high energy. It looks to me that it won't remain constant. A high speed motion should create strong ripples in Spacetime curvature.
Also, I am NOT talking about Quantum Gravity here in case you nag me about that. You don't need to give high energy to particles. There's no reason why a star or black hole can't be accelerated near $c$, mathematically.
How does Gravity behave at high energy?