Can I make an enemy sprite cover the entire battle field?

I want the start of the battle to be in complete darkness, then after some dialogue, it changes to show the enemy and the battleback. How I want to do this is to have the enemy sprite be just a giant black screen, then fade the screen out, and quickly add a copy of the enemy with the correct sprite and remove the black screen enemy, then fade back in. It works like a charm, except for one issue, the black screen sprite doesn't cover the menu, so behind said menu, you can see the battleback clear as day. Any idea how I can make the enemy sprite cover that bottom portion of the screen?

simply make a bigger sprite with any image program you like.

If that is not enough, we need a better description of your problem, preferably including a screenshot of it.

The sprite should be big enough to cover the screen several times over. But the UI stops it and you can see some of the real background behind it. Here, this screenshot explains better then I do:
There has to be a way to solve this, right?

I actually did a battle in darkness in my game, and the way I handled it was this:

Before battle begins:
Fade Out
Set Battle Back: None (make sure battleback 1 and battleback 2 are empty).
Use no sprite for the enemy at all.

That gave me a battle in perfect darkness in my game, though you could still see the menu just fine and select commands, and animations still showed up.

Not sure how to make an enemy suddenly appear from there though, you may have to use a battle command to transform the enemy when you want it to show a sprite, as I never tried that, as my case the entire battle was to be in complete darkness.

I want it to look as though the entire battle field reveals itself mid fight. So I made an enemy with a giant black sprite to cover the screen, then transform it into the appropriate enemy(or a copy of it with the right sprite) after fading the screen out, then fade it back in with all the new sprites and battlefield in place. It looks great, but I need the darkness to cover the whole screen.