**Study Overview:** This study is for adults who need a kidney transplant and are at high risk for a complication called delayed graft function (DGF). DGF can make it take longer for the new kidney to start working. The study compares a medicine called *ravulizumab* to a *placebo* (a fake treatment) to see if it helps the new kidney work faster. Participants will be given the treatment through an *intravenous (IV)* line, which means it goes directly into a vein. **Eligibility:** Participants must be 18 years or older, have end-stage kidney disease (ESKD) requiring dialysis, and be getting a kidney from certain types of donors. People with severe acute kidney injury (AKI) cannot join. **Key Points:** - Participation involves being randomly assigned to receive either ravulizumab or a placebo. - Treatment is administered intravenously. - The study will assess how quickly participants can stop needing dialysis after the transplant. This study helps doctors learn if ravulizumab can make kidney transplants work better for people at high risk of DGF.