Alan Moore may be ... eccentric, but he did some jaw-dropping comics. One of his Reputation Builders was his work on Swamp Thing, where he redefined a moldy Hulk/Heap mashup as an elemental creature, completely changing the tone and theme of the book, and the kinds of stories it could tell. The real genius of the hard turn he pulled was in doing so in manner that didn't invalidate anything we'd seen before; it's just that Alec Holland's memories were overlain on the muck monster, rather than Holland having become the muck monster.

So let's see if we can do it too:
  • Pick a DC Character, and make a major change by tweaking something in their past
  • Avoid anything that invalidates the major features of what's gone before
  • The more different or unexpected the outcome, the better