even so:spoken used to introduce something that is the opposite or very different from what you have been saying.

eg:i myself don't believe in ghosts.Even so, i wouldn't like to be along in that room at night.
even so是尽管如此的意思。（表示所说所做的前后矛盾）（我觉得这个是”转折）

even though：used to emphasize that although something happens or is true,something else also happens or is true.

eg:Even though he was tired, he helped me with my work.
尽管他累了，还帮我干活。
even though也是尽管如此的意思。（表示尽管某件事发生或是真的，另外的事情还是发生或是真的）（我觉得这个是”递进“）
看中文解释是一样的，但是看英文就不一样了。