Echoing Echo is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Target creature and all creatures that share a name with that creature gain echo until the end of your next turn. (At the beginning of the upkeep of each of those creature's controllers, if that creature came under its owner's control since the beginning of their last upkeep, they sacrifice it unless they pay its echo cost.)