This article examines the EUMR’s purpose and ex-ante control against the background of ‘killer’ or ‘zombie’ acquisitions that evaded scrutiny by falling below merger control thresholds, while other concentrations were permitted due to debatable market definitions or inadequate theories of harm. Recognizing these shortcomings, the article discusses ex-post control following Towercast and Continental Can. It submits that the conditionality introduced in these judgments constitutes (1) an effort by the CJEU to limit ex-post merger control, (2) an ultra vires restriction on the application of Art 102 TFEU, or (3) a de facto acquisition ban for bottleneck holders and ecosystem orchestrators.