So I want to create a character that is a god, pretending not to be a god. How can I make this character so that they retain some of their godly powers (They are the god of the night and can do pretty much do anything with nature)
1) So make a nature cleric/druid - that follows all the normal rules - who only uses his powers at night.
2) Play the long game. Use this same character/personality (no matter what class/mechanics) over the course of many campaigns, levels, editions, systems & years.
I have a character like this. Kelton Amberlord. He's based on the Chronicles of Amber. He'll "step into" whatever game we're playing & assume a role, following the same "rules" as everyone else. His favorite genres to go "play" in are D&D/swashbuckling types & he'll often appear as a bard/rogue/scoundrel type. Think of Q from ST:TNG. Or playing MMOs (though my character pre-dates MMOs by a good 10 years....) I've played him in every edition of D&D, a few Star Wars/space operas, a pirate game, andyes, Chronicles of Amber games.
And if I, as a player, slip up & say/indicate some kind of ooc knowledge? Well, Kelton IS a nearly omnipotent outsider....
If I'm using Kelton I'll give the DM a background. The 1st paragraph or two is background as pertains to the game we're playing - just like any character should have.
Then there's a red line.
Below that line is a section that details Keltons "true" origin as an Amberite. This really has no effect on the DMs game - unless they want it to. It's just there to amuse, informs more on WHY I'll do some things in character, & explains how/why the same character (character =/= stat block) keeps being used*.
(*The only game reason in which I will ever stop using this character is if he should get killed in a Chronicles of Amber game.)