El1vagar

El1vagar is Shiromi Matou's first Honmaru. This Honmaru was created on 15th January 2015 (IRL timeline). But, because of malfunction, Shiromi Matou left this Honmaru and got another Honmaru, 2flheimr (Read The Second Honmaru for full context). Previously, this Honmaru called Winter Castle/冬の城, as Fuyunotsurugi lived there for quite a long time. Winter Castle got renamed as El1vagar by Shiromi after this Honmaru got linked to 2flheimr. 

This Honmaru is not properly functioning for 100+ years, and got repaired after Shiromi attempted to access it again. This incident alarming the Government of Time about this Honmaru's existence, hence they also knew about Fuyu's existence. The Government hunting down Fuyu after that, and Fuyu seeking for asylum to 2flheimr. El1vagar got linked to 2flheimr and able to avoid Time Gov's radar. 

Currently, El1vagar is in a dormant state, but fully functioning with its own Touken Danshis. Shiromi Matou is still El1vagar's de facto Saniwa, but mostly they're operating on their own because El1vagar is not actively involved with front lines. It's used for a kind of 2flheimr's extension. 2flheimr is providing El1vagar's necessities, and El1vagar provides more land to cultivate for 2flheimr. 

Because El1vagar's Touken Danshis are recently summoned, they don't have any deep relationship with Fuyunotsurugi yet. But they treat her as a fellow swords instead of Saniwa. Fuyu doesn't have Saniwa's power, so they don't feel obliged to answer to her calls. Currently there are 100 Touken Danshis residing in El1vagar, and 2flheimr's Touken Danshis are still actively guiding them to their new lives.