dll-merger merges DLLs with one PE32 EXE and injects the loader code into the PE32 EXE and the injected loader loads DLLs manually without LoadLibrary and thus the loaded DLLs are invisible in the PEB.
Demonstration
Execute merger.exe procexp.exe MyDLL.dll
procexp.exe_out.exe is created
MyDLL.dll is manually loaded in the procexp.exe_out.exe when procexp.exe_out.exe is executed but it's invisible.