Please do not move the male!!!!!!! He needs to start eating obviously, and if you move him from the tank he's been living in and move him into a new tank, he's going to most likely suffer from a great deal of Relocation Stress, the main symptoms of which are a total lack of appetite, lethargy, etc. So as Venus already said, he could very well starve himself to death if you move him. You need to start getting nutrition in him, not making that situation worse....So let him be where he is, and as Cooper said, it's a good idea to tape some paper up on the inside of the glass so that #1) He'll feel safe and secure, and #2) So he won't be stressing out at his reflection in the glass...
As far as the "Substrate" goes that you're talking about getting for them tomorrow, what are you talking about? PLEASE DO NOT PUT ANY TYPE OF LOOSE SUBSTRATE IN EITHER OF YOUR DRAGON'S TANKS, THEY NEED TO LIVE ON A TOTALLY SOLID SUBSTRATE ONLY, ESPECIALLY IN THEIR CONDITION!!! I don't know what you're planning on buying, maybe you mean some textured, slate tiles or non-adhesive shelf liner, or reptile carpet. If so then that's fine. However, if you were thinking of buying them any kind of sand, crushed walnut shells, bark, wood chips, coco fiber, Eco Earth, any type of loose bedding, like rodent bedding, etc., please do not waste your money. You would only be putting them in danger of either becoming impacted, and/or developing multiple infections. Neither of them have very strong immune systems right now, and ALL loose substrates, regardless of what they are, both harbor and breed multiple types of harmful microbes, such as Bacteria, Fungi, Parasites, etc. So you'd only be putting them at risk for developing an Upper Respiratory Infection, a Skin/Scale Infection, Eye Infections, etc. You need to keep them on ONLY A SOLID SUBSTRATE, such as the Textured Slate Tiles you can buy at Lowes or Home Depot, Non-Adhesive Shelf Liner, Reptile Carpeting, etc. You're much better off with just putting down Paper Towels or Newspapers and changing them out when they get soiled than you are putting them on a loose substrate, they just cannot handle that.
******The most important thing that you can do to put weight on the male, to get his immune system up and running, and to increase his overall health and ensure that he's not going to continue to suffer from any Nutritional Deficiency Diseases is getting him under a very strong
UVB light. He's not going to every have much of an appetite until he's getting adequate
UVB light right next to a bright-white colored Basking Bulb, both over the top of the Hot Side of the tank, right alongside each other, with his basking spot/platform directly underneath both lights. And make sure that both lights are on every day for at least 13 hours.
I highly suggest investing in a long UVB tube and long tube fixture for it which has a reflector inside it, so that he will get strong
UVB light not only right underneath the tube, but all throughout his tank. Both Dragons need their own very strong UVB tubes, this is not optional, it's the most important piece of equipment you will every buy them, and since the male has been totally dominated and robbed of most of the
UVB light they were getting when the were together, it's probably a given that he is suffering from a Calcium Deficiency and MBD, as well as obvious growth and development stunting. So the ONLY way to reverse this and to get him gaining weight and growing is with a very strong, T5-strength UVB tube and fixture. That's your answer.
Dragons do most all of their growth and development during their first year of life, so they both have time to grow yet. But obviously it's going to be crucial for the male to get strong
UVB light and a ton of live insect protein every single day if you want him to even have a chance to catch-up in size, reverse any of the physical disabilities caused by the Calcium Deficiency and MBD, and for him to have the large, healthy appetite that he needs in order to start eating a large amount of live insect protein daily. So you need to get him a T5-strength UVB tube that is at least 22" long, and that is at least a 10% UVB tube, or a 10.0 UVB tube (NO 5% OR 5.0 TUBES)...
Buying UVB tubes is expensive in pet stores, and most all of the tubes you see for sale are the much weaker T8 strength UVB tubes, which cannot sit on top of any type of mesh lid because they are too weak to penetrate adequate
UVB light on the other side of the mesh to your dragon, so they have to be strapped to the underside of the mesh lids. They also have to be within at least 6" of the Dragon's basking spot/platform, and they must be replaced once every 6 months on the dot, as they have a very fast UVB decay rate, and at 6 months old they stop emitting much
UVB light at all.
In contrast, the much stronger T5 strength UVB tubes are strong enough to sit on top of the mesh lid as long as they are within 10" of the Dragon's basking spot/platform. Another plus is that they only have to be replaced once every 12 months. So you save a lot of money over time.
The cheapest place to order a T5-UVB tube and fixture is on Amazon.com. For about $60 shipped you can get both a 22" Reptisun 10.0 T5HO UVB tube and then also a 24" T5-rated (24 watt) tube fixture that includes a reflector with it. This is how you are going to get him eating, growing, and putting on weight.