Pick an acquirer and a target, set the deal terms, and the model builds a real purchase-accounting combination: goodwill and core deposit intangible, fair-value marks on loans and securities, cost saves, the CECL day-two provision, and a recomputed capital stack. The output is the line that matters in a board memo, what the deal does to ROA, ROE, ROTCE, the efficiency ratio, capital ratios, and tangible book value. Everything recomputes as you move a lever. Seed values pull from FDIC data and every input is editable, so you can run a real bank or your own numbers.