For good and Until doomsday

For good adverb - For a long time without essential change.

Until doomsday and for good are semantically related. in for keeps topic. In some cases you can replace phrase "Until doomsday" with "For good", this phrases are similar. informal substitute

For good and until doomsday are semantically related. Sometimes you can replace phrase "For good" with "Until doomsday", this phrases are similar.