To avoid revealing context of my question I will use an example.
Let's say I have a business, could be plumbing electrical consultation whatever. And to promote my business I come up with a gimmick or slogan of.... Idk... "Ironclad work from ironclass workers." I like my slogan and what it represents for my company, so I take the basic structure of iron Man's helmet, change a few of the lines, maybe space the eyes and nose differently, and render it in new colors and textures to reflect the element of my business. We will say that my business is steel work. So now I have a logo for my company with my company's name and my company slogan and the only thing I'm taking amuse from is the overall design of iron Man's helmet. Very clipart and plane. The ultimate basis of my question is... How much do I need to strip from the original copyrighted character, in order to avoid copyright infringement in this particular case? Another simple example would be to make SpongeBob SquarePants a wider rectangle with red pants and green skin with no holes.... How abstract does the new character need to be so that it does not cross copyright infringement? Especially with a company like Disney.
Can I create my own costume of my own character with his own background that follows the similar guidelines of the character iron Man? How many of those characteristics do I need to alter?