Besides setting interest rates:

In 1932, Congress gave the Federal Reserve the power to lend money to “any individual, partnership, or corporation” during “unusual or exigent circumstances.” The Fed used the emergency-lending provision to make a few modest loans during the Great Depression. The power then lay dormant until the 2008 financial crisis, when the central bank issued hundreds of billions of dollars in loans in an effort to rescue major financial institutions on the brink of collapse. During the height of the coronavirus pandemic, the Fed went even further, offering trillions of dollars in loans not just to big banks but to corporations, small businesses, nonprofits, and even city governments

And:

Perhaps even more alarming, control of the Fed would give the president a powerful weapon for punishing his enemies. The Fed is the central node of the U.S. financial system. Every major bank in the country holds a master checking account at the Fed, which they depend on to make and receive payments, manage their reserves, and access credit. The central bank, in turn, operates as the country’s main financial regulator: It determines whether banks are in compliance with existing laws on financial risk management and illicit transactions, for example, and has various ways to enforce that compliance, ultimately backed by the threat of cutting off access to the financial system altogether.

The tools Trump has used so far to bend institutions to his will, such as withholding federal funding, are powerful, but they pale in comparison to the power of debanking.