Hi Jayson, Thanks for contacting us! The closest thing we have is the Seasonal tab > Holiday > Snow effect which looks quite a lot like rain if you reduce the amount to around 20% and fade it up to around 70%. Let us know if you have any further questions!
You’re welcome! To combine two images, you can create a simple collage by going to the Home tab and clicking the Create Collage button, and then selecting one of the 2 photo layouts on the top row.
The other way is to start editing a photo, and then drag on another photo from the Photo Basket at the bottom of the editor. You can then delete areas from this second photo by using the Eraser Tool. This is a better option for when you’re trying to move an object from one photo into another. You can watch a brief demo video here.