In the underground room stood Yurei
In a cross legged position with a strange black and green aura surrounding him kind of like broly's ki aura while going in ikari state
Yurei :" it's been six months since I started training in magic and it seems I've found my unique magic" he then grins like a mad man because over these 6 months he's been perfecting his mana control and manipulation aswell as being more creative since you need to have a good imagination to release magic and powerful spells at that and after these 6 months he has finally gotten 100% over his mana and his current magic circuits he can now create fake versions of weapons that are 75% as good as the real versions of them. By far his favourite weapon to create is Shisui from one piece mostly because its quasi indestructible making it one of the most convenient weapons he can posses. But aside from that he found something interesting about his mana it was quite dark ominous but calming and through deep searching into his origins and a bit of thinking he realised it was a type of advanced dark magic unique to only himself it mainly is phantom type but also a deadly erasure and steal type and from all of this testing such as instead of absorbing mana from the atmosphere he just grabs it and rips it from the atmosphere like how the death reaper from naruto takes the users chakra making the mana he takes more potent and destructive also allowing him to make himself intangible to a certain extent like a logia unless the opponent hits him with a mana covered attack but even then if he focuses enough and is calm about 20% of the mana infused in the attack can be absorbed by himself but cannot be used until the next day
Yurei :" it's seems as if I can steal mana externally but can I steal mana internally like the opponents mana cuircits from them? Well currently I have no test subject for that at the moment so I'll just have to wait until the holy grail war to test it" after finding out this he proceeds to use gradiation air and make Shisui and imbue his unique mana with his special attribute of intangiblity
The outside appearance of Shisui didn't change to his perception but since his room was filled with mirrors he noticed that to another persons eye it was invisible he smiled at this it was a good card to have under his sleeve after all after he finished admiring the invisibility aspect he tried swinging it at the 4 concrete poles ahead of him as he tries the sword completely phases through all of them.
Yurei :" thats kinda disappointing-" but just after he finished that sentence the 2 poles behind the first two came crashing down
Yurei :"OOOOHHHH SH** HOLY GRAIL WAR IS GONNA BE DOMINATED BY YOURS TRULY".
He was ecstatic at this result because not only could he now do the anime swordsmen cut he can phase through and cut at the same time but he could already tell it would be random where the phased cut would land unless he perfected it. He continued to test the limits of his new found magic he then realised he can't really do that without another mage but he did name this magic he discovered
Yurei :" Gensō karito magic" it translates to illusion reaper