From what his ancestors extracted from the intruder [Dream-Walker] to enter someone else's Dream the walker needs to conceal himself with his own realm, then stalk the necessary Vis Beasts, ambush them and after killing them absorb what was left of their existence, if the walker chose the right spirit then the information he would extract should be fragmented after the beast's death and it depends on the walker's ability to assimilate as much as he can and then remember the beast's signature and hunt it again until he won't extract the full information.
Without a dream realm in his possesion - he would've been constantly attacked by [Nightmares] - a subcounscious countermeasure to foreign beings if the dream holder is sensitive enough, some sort of antibody reaction in his opinion.
Then he would've been used as some sort of snack or toy, depending of the source they appeared from, [Dream-walking] is extremely dangerous without owning a [Dream Realm] or having spiritual or dream spells/abilities or some advanced concealment abilities.
With him only being introduced to actual spells only after dying and through a book - not a real teacher, he profusely thanked his past self in his mind for having a controlling streak a mile wide that got under control even his dreams his [Dream-Walking] ability, 'now at least I won't die twice in a row, which, admittedly, would've been certainly amusing but I'll pass' he convinced himself while thanking his nonexistent lucky stars, developing his own talents certainly paid off.
He'd seen already how colossal mountains blowed up into an everlasting pink and fluffy blanket, while he was falling from the purple sky attempting to assert some form of control over the realm around him, he even succeeded slightly at it with the motivation of not becoming a pancake which really made him paranoid even more than he naturally was.
Such coincidences weren't at all something new with how his old world's suppression worked, 'but not on a natural disaster's scale, cmon' he thought displeasedly.
'I swear to get some sort of flying, even if I like pancakes but not on this level!!' he noted the thought down in his mind, seriously not liking the perspective of becoming flat.
He considered the instance of him himself becoming a cloud with the instant enviromental changes around, even if that sounds wonderful and better than a pancake, he does appreciate his own body and his daily life enough to not desire a spontaneous change.
He'll shelve that on his future self, in his Grimoire there was brief description on shapeshifting and having multiple forms.
'I'll get to become whatever the hell I want, even a fluffy cloud, while having the option to revert back to my original form, that's hella nice' he appreciated the thought immensely.
The sea of clouds made him really curious so he naturally decided to get a pièce of his own, a comfy cloudy blanket or pillow sounded highly appreciated by his tired mind.
He started by enveloping a part of the cloudy mass with his own energy derived from his realm, infused it with his own essence from his heart, infused it with his thoughts, and how was written in the [Dream-Walking] section - with his desire of flying, freedom and stability.
Condensed and shaped it into a comfy looking big pillow. Then animated and enchanted it with the spells [Animate] and [Enchant], that he picked up from his new Grimoire to check how the spells even work, and finished the work by connecting it to himself.
The pink fluffy mass under his influence begun to condense in the shape of a pillow the size of his body, then transformed into a cartoonish pink cloud then back into a pillow that was slowly floating in front of his face.
Now the fluffy thing is part of his own illusory dream realm, he can summon and unsummon it at will.
He's very proud of his own work, using his bloodthirsty's ancestors magic that summoned spirits and devils, daemons and apparitions while torturing them all for information and into obedience, to be the most comfortable he can be while adventuring, the thought of them rolling in their graves amuses him greatly.
And he even got the hang out on how to use the Grimoire and how to absorb the knowledge from it, even though he awakened with the basic information already appearing in his head which included the instruction on how to use the book as a focus while casting the spells inside almost not spending mana on them, to boost them and gain control upon them he will need to revive himself to get his prana out of stagnation and stasis.
And even though he created a simple artifact he will need to rework it later to streamline the spells and make it cost-effective, at least from what he can sense it will work nicely and will use the energy in the dream realms because of its origin, plus the nature of the realm keeps the construct stable until another abrupt change but it will pretty much destroy itself out of its boundaries unless the next realm will be stable too and part of a Dream realm.
Because the pillow construct is connected to his own realm it would only weaken itself in another Dream Realm, with some slight adjusting to the new enviroment it will probably work again, he will see in time.
Seeing how he got the hang on how to interact with the Dreams, he obviously stuffed a lot of clouds in his own realm to experiment later on it, when stuffing them in he made sure to not be too greedy and take too much from one place, the lurking Nightmares below the cloudy surface it's not something he wants to disturb.
Dream materials, from what he did read, are very useful for getting new affinities, creating new spells and abilities or creating growth-type artefacts.
Certainly an interesting niche for him to study and experiment in later when he's in a safe place and not dead.
He can't wait to get some free time to finally become a normal-ish mage, being suppressed to only internal energy control by his old world was certainly unamusing, even if he got very good at it in his humble opinion, he wanted to do something flamboyant!
Something colorful and magical, something that is external and not some weird Yin Qi Sutra for hunting and cleansing spirits or Wood Qi Sutra for meager energy regeneration - this sutra he mainly used to have a tug of war with Forests mentally to sharpen his mind with the gains from the Yin Qi he gathered from work.
He's fed up wih those already even if he's not bad at them, throwing hands with spirits was challenging and fun only at the start of his career, lately it transformed into bland rutine and he did it only for the money, his progress in the oriental techniques stagnated too, it's not like he wasn't capable of forcing his way through the soft cap but the passive "Heaven's Will" will curse him with more unluckiness than he can afford.
The supernatural path was followed by unluckiness in the modern era, if he wasn't blessed alredy he wouldn't mingled with the supernatural.
Now he can say that the blessing was from Morrigan, he isn't even surprised.
After getting done with colecting accurately the material while pondering about his future he activated his senses to maximum along with his insticts, 'the path out is near, I can feel it' he noted while readying himself.
Floating on his very nice pillow toward a red looking cloud patch he got excited, finally something different! He cautiously approached the crimson anomaluous area and started to observe every inch of land:
Red bloody clouds and a creepy skeleton lying on them with the clouds around him being a lot darker, 'someone's reamains, great, it certainly made me more assured of me swimming earlier through this cloudy sea, what a close call, darn it' he thought disgruntedly.
He's even smelling something, that's great, he thought this realm can't support some of his senses, that already happened in the past, such thing shows that this Dream Realm is an advanced one, probably formed through a lot of beings dreams.
'This red patch of clouds is certainly weird, even by weird dreams standards, I'm not one to judge though, I'm not someone very experienced in varied dream structures but from my experience the Dream Beasts dissappear after death rapidly, one-two minutes and Poof, they're gone, blended in the Dream's atmosphere'. Demeter pondered on the strange reamains origin.
The place reeks of blood, some sort of viscous mana, calcium, vitality, concealing, animosity and strangely perception through his senses.
'It's surprising that the creatures below didn't devoured the remains, the being that died there did had probably some sort of camouflage ability that works even now.
How did I even found it though? Weird stuff, man.'
He stopped and scanned everything more closely, his instincts picked up a possible entrance to somewhere, a somewhat safe passage which will be his way out - he can feel, his instincts even hinted that it's a somewhat safe passage.
He will deal with it later, first thinghs first - it's looting time.
He fished out the skeleton accurately into his realm, it even got a pair of eyeballs in his skull and even a purple crystal heart that looked like crafted by a glass artisan, everything is intact at first glance and won't break at first touch.
So obviously the loot goes to his own realm now that he can store things in it, even if he has to strain himself a little to succeed he's okay with that.
His soul reality is at the same level as the red clouds so straining a bit is understandable though not pleasant.
Loot is always fun to scavenge for in his opinion, 'this time it's even some cool looking remains of an unknown native humanoid.
I become a grave raider, how low can a looting addiction take someone? The answer for me is certainly 'not low enough', bruh'.
Just after he expropriated the free cloudy estate which consisted of the red clouds around - the hole that got into its place sucked him in like a very experienced lady.
'Finally a change of scenary' he thought while a multitude of colors in the form of a wormhole sipped him all in.
His instincts didn't mind so it means he's safe for the time being.