My first summer in the Sierra- When we try to pick out anything by itself, we find it hitched to everything else in the universe (B+, Anti-World): A Noble Phantasm that fulfills Caster's life work of Conservation, which he referred to as Preservation. Caster believed that through seeing the world as the work of God one could become far closer to him than through the Bible or other religious texts, he tried to encourage all around him to see the sublime nature of the natural world and was incredibly successful, leading to the formation of the first National Parks. The Noble Phantasm takes the form of a small battered book, like Caster's other clothes it is weathered down through constant travel and wandering. It fits into a pocket with ease and within contains a series of small notes by Caster, these would be instantly recognisable as being from Caster in life to many. Caster "plants" the book like it was a seed, from the ground grows a large tree, it has the same properties as a regular tree and as such can be easily uprooted and destroyed, requiring the Noble Phantasm to be restarted from the beginning. Within a few minutes the tree grows from sapling to full height, for those who are completely detached from Nature, viewing it as a means to an end or a purely material thing, the tree will appear to be nothing more than a regular tree (albeit one that is exuding obvious mana traces). For most however a sudden moment of awe will occur, although this will have no lasting effects. The tree taps into the surrounding laylines and spreads out into the world through a warm steam, mirroring the geysers of America. It is an ever expanding Bounded Field that converts Mana in the environment to it's goal of Preservation, slowly rewinding the world around it. Heroic Spirits will find themselves empowered as the world turns back to the time they lived in and Mana will be present in excess. As such it may appear to be counter intuitive for Caster to use this Noble Phantasm as he himself lacks any offensive or defensive measures that he can use and the Noble Phantasm is almost like a flare for even the most simple of Mages. However if given but a matter of three days the immediate environment of the tree becomes truly returned to it's natural state, it becomes a "Hole" to the Reverse Side of the World. Though this can be dangerous as Caster has no direct control of the Phantasmal Beasts they are unlikely to attack him due to his close connection with Nature. After a week Caster's Noble Phantasm will begin to reveal it's true nature. Summoning an incredibly powerful Phantasmal Beast which Caster refers to as God, this Phantasmal Beast possesses unmatched control over the Bounded Field, capable of recreating Mysteries related to Nature. Roots will move with incredible speed pulling down Heroic Spirits, a Glacier can suddenly appear to crush a foe before suddenly dissolving into mist. Ultimately Caster and this Phantasmal Beast have the same goal in mind, the cementing of this "Gods" power over the World, cutting down the Counter Force and making itself the most powerful entity. However whether it is benevolent remains unknown.
Though it does provide an environment that Caster can hide in due to his Crossing Arcadia skill, and it may eventually prevail in the Grail War, it is still a Noble Phantasm that needs great expenditure of resources to provide the time necessary for the Noble Phantasm to complete it's work.