Decided to take a look at DC Hitler. See some of the stuff they've done with him.
During WW1, it would seem that Hitler, Stalin, and an Asian man I can only assume was Tojo all met Anton Arcane, at the same time, while he was in the early stages of experimenting with necromancy. With Anton Arcane even trying to claim that he manipulated Hitler into starting WW2 just so that he'd have access to more corpses. Which is fucking retarded. If you need to trigger a war on that scale just to get your hands on corpses . . .
He obtained both the Spear of Destiny and the Holy Grail. Using the Spear of Destiny, he almost killed Green Lantern (Alan Scott) and The Flash (Jay Garrick). He was only stopped because The Spectre intervened.
With the assistance of a Japanese sorceror named the Dragon King, a mystic barrier was raised over the territories owned or occupied by Germany or Japan. The Spear was used to create the barrier over Germany. The Grail was used to create the barrier over Japan. These barriers would corrupt any superheroes who tried to intervene in WW2, potentially brainwashing them into fighting for the Axis. Apparently it was extra effective if used against magical superheroes. (Imagine if the barrier worked on mere mortals, too, and not just superheroes.)
Whereabouts of the Holy Grail are currently unkown. As for the Spear of Destiny . . .
Towards the end of the war, as it became clear Germany was going to lose, it was used in two separate attempts to destroy the world.
One attempt had Hitler perform a ritual linking the universe with Ragnarok in a way that would apparently retroactively cause the destruction of the universe or something. This was stopped when Doctor Fate transported the Justice Society to Asgard so that they could help the Norse gods prevent Ragnarok.
Another attempt was when Captain Nazi tried to use it to kill The Spectre, which apparently would have caused the end of the world if he'd been successful.
The last thing Hitler ever did with the Spear was corrupt it in such a way that if anyone else should ever wield it, they'll be infected with his greed and lust for power.
Then some shit happened, it was cast into space, it was recovered so more shit could happen, cast into space again, recovered again so even more shit could happen, and, well . . . I think the last time it was ever used, it was used by The Spectre after being purified of Hitler's taint.
But Zoat has said that The Spectre doesn't exist in Earth 16, so bare minimum you can ignrore anything that involved The Spectre. (In which case, I wonder who saved Green Lantern and The Flash?)
And if none of the stuff involving The Spectre happened . . . The Spear was recovered by the Allies and is currently in storage somewhere in the United States.
As a final note . . . DC Hitler was killed by an American operative known as the Unknown Soldier. He snuck into Hitler's bunker during the Battle of Berlin, killed Hitler, impersonated him so as to cancel the deployment of some last ditch Nazi superweapon, and then made Hitler's death look like a suicide.
For the curious, the superweapon was a bunch of some kind of Human-Octopus-Vampire hybrid called Nosferatu. Though I don't imagine they were too big of a threat, as they would have had to have been dealt with anyways even if they never got deployed.