Apparently, moving an entire house's worth of ethereal energy and condensing it into a single room is... difficult, to say the least. The room Wayne chose to put it all in was none other than the back of the kitchen. Who checks the kitchen, right? He would check where the ghost died, or the ghost's room or something. Of course, if they checked more than just the general area he would be faking his death, he could already kiss his unlife goodbye.
Then the fact that his life was on the line sunk in. He was suddenly overcome with extreme dread completely out of the blue. Consciously, of course, he realized he might actually be dying for good here. But that and fully realizing that there might just be... nothing, after this, was another experience entirely. He couldn't allow his nerves to get the better of him right now though, it would only end in his death if he did.
Instead of dwelling on his sudden existential crisis, he decided to distract himself with the inane amount of energy he was trying to influence. It was like if someone had a hundred little hands to catch thousands of little ants. And each ant weighed a pound. A strange analogy, he had to admit, but oddly accurate in describing the feeling. The fact that he had to give conscious effort into making the energy pass through solids didn't help either, even if it was relatively easy. Needless to say, he wouldn't be able to do this on short notice, especially with the unknown amount of time he had to practice. He had to do something differently. But what? Maybe he was thinking on too large a scale. Perhaps, he could just push the ethereal energy out of whatever room they were in. It seemed more plausible than compacting all of it in a singular space. So he decided to try that instead. Focusing his mind, he reached out with his ethereal energy and pushed it out, catching the ambient energy on it's journey, willing it to not interact with anything physical. It was a strain on him, mentally, but he managed to lower the levels by a significant portion. With just a bit more practice, he could probably manage to make it low enough to be indistinguishable from the amount outside.
In fact, it would probably be easier wherever the ghost hunters were checking. The kitchen wasn't the largest room in the mansion, but it wasn't small either. It was certainly bigger than his room. The smaller the room, the less he would have to actually move the ethereal energy. He would continue to practice here, of course, because that would make moving whatever he had to easier. It was sort of like how martial artists would train on the tops of mountains, because the higher altitude made it harder to train, and therefore had more benefits. He didn't really know how it worked, it just did. Still, the activity was leagues easier than what he had been trying before.
He continued like this for another hour, until just before the sun rose. It had now been two days since the Day of Undeath, and he imagined the hunters would come either today or tomorrow. Assuming ghost hunters arrived at the site of a monster attack at around the same time as other hunters, which might not be the case because of ghosts not posing a threat to anyone outside their haunt.
It was still better to be safe than sorry, however, and Wayne did not want to end up facing an entire squad of people whose entire job is to kill his species of undead on low ethereal energy. With nothing left to do, Wayne figured he might as well make himself look presentable. Not that he thought he could change anything about his appearance, being a ghost and all, but he just wanted to look at himself in a mirror, really. He was fairly sure his clothes were part of him now. Did that mean he was technically naked? Either way, Wayne was already floating in front of the mirror, and looking into it he saw... Nothing. He could see the rest of the room, that wasn't the issue, but he himself wasn't appearing in the mirror at all. Right, he was invisible... No, wait, he did something during the Day of Undeath to become visible. Looking back on it, it was definitely a conscious action. it was an instinctual reaction, like moving a muscle. He just had to... There! He was in the mirror now.
His appearance had changed very little since he was alive, he was even wearing the clothes he had on at the time of his death. The only two things different being the red slash on his chest, and the blue glow radiating from him. The dusty mirror didn't give the clearest image, admittedly, but anything he couldn't see would be too minute to mention. He ineffectively brushed the front of his shirt and smoothed his hair to no effect. The actions made him feel more confident, even if they didn't do anything to actually change how he looked. It was stupid, he knew, but raised his self-esteem anyway.
Well, back to playing ping pong. The game had gotten so trivially easy on his ethereal energy that unless he tried to accelerate the paddle to a frankly wasteful speed, he could hardly notice the drain on his power. His skill had improved immensely as well, unsurprising with how many hours he sank into the game.
It was his third game by the time the sun shone through the window. It didn't reach him, only shedding a brisk morning light into the room for a few feet before dispersing. With it came a quiet murmuring, and looking out the window, Wayne could see a group of five approaching the mansion. They were dressed head to toe in white garments. Every inch of skin save for their face was covered by white clothes, from boots to gloves to hoods. Preparing himself, Wayne went down to the first floor. This time, he would come out on top, and nothing was going to stop him.