It wouldn't be a transfer window for Chelsea without Eden Hazard mentioned. The Belgian brings a sense of warmth and certainty to the minds of fans, especially in a time of major change.
Even when Hazard was a Chelsea player his name was linked with moves away from the club. As the club's main attraction, he did his fair share of flirting during those years as well. The move to Madrid was inevitable in the end the magic was not just getting another season out of him, and a truly great farewell in 2018/19 it was, but also receiving in advance of £100m ($124m) for him.
Marina Granovskaia secured what turned out to be one of the best deals in the club's history. After Madrid won the Champions League in 2022 they had paid extra for Hazard and as his career at Santiago Bernabeu comes to an end, his seven goals cost nearly £15m ($17m) each.