Felix managed to steady himself. Using the hand that was still placed on the tree to support himself. The acorn had fallen from the small branch on which it grew. Felix bent down to pick it up. It hummed with magic. He rested at the base of the Oak tree for a few hours. When he got up it was midday and the sun was high in the sky. Only half of the magic in his core had been replenished in that time. He made his way to the druids' grove. So long as he stayed there non-magical folk wouldn't be able to find him at all. And if there were any magical people out there most of them wouldn't be able to enter either.
The runes which he inscribed into the trees were powerful wards which would ensure that only a suitable candidate could even find them. Now that the candidate had been found and the ritual had been done, the only person who would be able to enter was Felix and any he allowed in. Someone trying to find him would first have to know which runes he used for the wards before he could even begin to find him. The land was for all intents and purposes unplottable, not even blood magic would be able to locate Felix.
Once he reached the grove he found a suitable spot to plant the acorn. He would have liked to place it in the centre of the grove where the stone was, by design that is where the magic was concentrated the strongest. But if he moved the stone even non-magical people would be able to find the grove. It was so intrinsically bound to the wards which hid this place. It had to be given that it was a key part of the ritual. Felix planted the acorn a metre away from the centre. Now all he had to do was infuse it with his magic three times a day at the same time every day for the next 2 weeks.
Time Skip
Two weeks have passed during this time the acorn has grown into a sapling. It was about half the height of Felix. It was almost done. The sapling had a trunk which could be gripped comfortably in one hand. Towards the end, it had a couple of branches. The branches were bunched up; they didn't spread out; rather they grew straight up; they were half the size of the main trunk, all of them roughly the same size. Creating a circular shape at the end of the trunk. To finish the catalyst off he would have to find something to put into the circle. Once he did that the branches should coil and wrap around the object. The final shape should be oval with a point at the top. What he placed at the end of the focus would be entirely up to him.
Most druids would place a plant or flower which held significance to them. It would grow as they used the focus. Wrapping around the magical sapling increases its connection to certain aspects of nature depending on what plant was used. Some would use animal bones, to give their magic the qualities of the animal whose bones were used. And he had heard tales of some people putting precious stones in the centre of their focus. This was supposedly done to increase the user's potency with soul magic. As certain stones could hold souls and harness their energy from them. A terrible fate to be trapped in a soul gem. Until it was used up the soul inside would be stuck inside conscious of what was happening. Upon using the soul energy it would dissipate as another soul would.
He had learned a great deal of soul magic particularly its uses in rituals. A horrifically wonderful branch of magic. Something one shouldn't dabble in lightly. Making a mistake while attempting soul magic could have the most brutal of consequences. Felix was racking his brain but he had difficulty remembering most of what he had learned, he couldn't even remember how the ritual he performed worked. It was something which was so close yet he could never reach. Felix had mostly been scavenging food twice; he hit a rabbit with a rock and caught it while it was still dazed. During his two weeks in the woods, he had eaten better than he ever had with the Dursleys. He always made sure to stick within a certain range of the grove. This was to ensure that even if he left the range of the wards he would be able to enter them quickly if someone spotted him. Once or twice he heard distant shouts of "Harry Potter." He was half expecting the Dursleys to pretend nothing was wrong.
Felix decided to go search for a plant to place in the middle of his focus. He decided on atropa belladonna commonly known as belladonna or nightshade. A deadly poisonous plant which symbolises silence and falsehood it would aid him greatly with poisons and illusions. He found some amongst some shrubbery. He picked the flower of the plant and he took it back to the grove. He pushed some of his magic into the flower before he placed it into the centre of the focus. The flowers grew a stem and connected with the trunk of the sapling. The branches began to coil around the flower and create an oval shape with a point at the end. The flower was encased by the branches. Now all Felix had to do was infuse it with his magic one last time and in an hour cut the sapling down. After chopping it down. It would become apparent if he was successful. He decided that the best size would be the size of his forearm and his hand. He would carry it around like a sceptre. After he infused it with magic for the last time he waited an hour before cutting it to size.
The cut began to heal over bark beginning to grow on the newly created stump and the end of his sceptre and Felix was left with a working focus. It was by no means good quality. It was rather basic. He just didn't have the magic to facilitate any more growth within the allotted time. The one thing which Felix always found interesting about druidic magic is that a substantial amount of it could be done with little control and direction required. The plants would grow on their own. All the druid did was give the energy to facilitate the growth. Nature had a will of its own and commanding its magic was rather difficult without its cooperation.
This would do for now, but in the future, he would have to craft a more powerful focus. The only good thing about the method that druids use for creating foci is that the focus grows and increases in power the more it is used. Such growth had its limits but would be useful nonetheless. Felix spent the next two days practising magic. He needed to practise his illusions if he wanted to return to the Dursleys with minimal consequences. The night before he showed himself to the Dursleys he went to the house and cast an illusion which would prevent the outside world from seeing what was about to happen. He pulled out his sceptre and his magic flowed through it.
"Imago integumento," he whispered.
A blanket of magic fell over the house and the nearby area. In a radius of 2 metres from the was a shroud of magic which would show the image of how the house had been when the magic was cast. It was a simplistic spell, one which was useful but limited. It created a still image. If any person or animal were present when it was cast they would appear to anyone on the outside standing perfectly still like a statue caught in the action which they were performing when it was cast.
For his purposes, it would suffice. There was no need to show off and use magic which would be a bigger drain on his magic. It was a good thing it was such a calm night, had it been windy someone might have noticed the tree in the garden not swaying in the wind. Another which he had forgotten to account for was torches and flashlights, they wouldn't light up the house if their light was shined upon it. This was something he would have to remember when using this spell.
Felix stepped into the area of the spell and to any onlooker it would have appeared as if he had vanished. He began to circle the house dragging the tip of the sceptre gently along the stone of the house. He was muttering incantations. After the first lap, faint runes began to appear on the bricks of the house. He continued 3 more times until the runes were bright enough to give off a bright yellow light. Once he took the tip of his sceptre off the bricks of the house the runes disappeared without a trace. The runes would make the inhabitants of the house docile. It would take someone a few days of exposure to them for it to take hold fully and would begin to fade shortly after leaving the home. It was simple and difficult to detect, but once one knew of its existence its hold over the person would diminish. No matter if they were magical or not.
If one had any basic training in the mental arts they would at the minimum feel it intrude upon their mind. Soon the 3 Durslesy would be in a haze, just going through the motions. And their nephew wouldn't even register in their minds.