Q: What is the limit of replication in UBW? The highest level of NP (sword types) is probably Ea, but while it might be impossible for Shirou, could Archer make it? Also, under the meaning of weapons, to what extent can he make modern weapons? Must it be only blade types or can he make guns and mobile weapons?
A: Divine constructs like Ea and Excalibur are non-replicable. There might be some degraded NPs with similar performance in stock though. Also, since sword is becoming his origin, the weapons that he has stored are fundamentally limited to close combat.Other way around. Sword became his origin became his alignment.The absoluteness called Origin
If alignment determines the root of one's magic, then even deeper than that, is the origin which determined the root of one's existence. The origin is not only for magi, but is the orientation that all things are born with and it's existence itself is thought absolutely necessary.
Those magi with an origin that is strongly expressed outwardly are sometimes removed from the normal alignments and there are times that the origin itself becomes the alignment. Most of those magi exhibit their talents as extreme specialists.
Because of that, it's said that they can reach higher grounds than normal magi.
Emiya Shirou's origin is "sword" and his alignment as a magus is also "sword". Because he doesn't have one of the five great elements as an alignment, he's not good at magic using the five great elements. In exchange, he can manifest Reality Marble "Unlimited Blade Works."
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An instance of magi saying "origin" to mean "alignment" is this:
So that leaves only one method open to me.
According to Kiritsugu, every person has at least one form of magic they are fit for.
He said something about drawing out magical energy appropriate to their "origin", but I didn't really understand.
All I know for sure is that even I have some magic I can use, and if I train that magic, I may be able to become like Kiritsugu.
That is why I learned only that magic.