Corporations (Inc.) are taxed as entitites of their own, like a German GmbH.
Single-member US LLCs (you being the only shareholder) are tax-transparent, i.e. taxed as if you yourself had earned the income personally (like a sole proprietor).
With a US corporation + Malta residency, his thinking is probably that you will be paying US corporate income tax on the profits (granted, it seems like there are some states without CIT or where CIT is low) in the US and then only pay income tax in Malta on profits that are remitted to Malta. Delaware does have corporate and franchise tax, you could have easily︀ googled that.
There is a small risk that when you work from Malta, they will︁ not treat the income as foreign-sourced and will claim you have a permanent establishment in︂ Malta, for which you would have to pay Maltese taxes. They could probably even claim︃ your US company is really tax resident in Malta - but that's also unlikely. Cyprus︄ might be a better choice as I think they don't tax foreign dividends at all,︅ but there's a lot of uncertainty as well. Some people say it works, others say︆ it doesn't. Note that you will - at least officially - have to spend at︇ least 60 days in Cyprus to be considered tax resident there, I believe the requirement︈ is even higher for Malta.
German law probably requires you to report all companies that︉ you own abroad in your tax return, like most high-tax countries. If you "forget" to︊ report the foreign company, they can charge you with tax evasion. But if you don't︋ make millions and will leave the country in a few months anyway, it seems highly︌ unlikely that anyone would go after a small fish who doesn't even live in the︍ country anymore, even if they found out later. Just be aware that it's no