u/Environmental-Mail89

Three people are in a realtime group call using hypothetical faster-than-light communication:

One remains on Earth.

One is already near another star system.

One travels between them at relativistic speed.

Since communication is instantaneous, signal delay is removed, leaving only relativistic effects.

How would time dilation and relativity of simultaneity appear to each participant during the conversation, and would they disagree on whose clock is running slow?