Extra from issue 2014-10 of Monthly Shōnen Ace, where the manga adaption is featured in.
You should still be able buy it secondhand from various stores, such as Amazon.co.jp ; but obviously you need to figure out how if you're not in Japan.
Edit: it seems two secondhand ones for sales don't have the poster. The "collector item" one does have the poster, though. Changed the link to direct to that. There is one (poster only) for sale on Suruga-ya, too.
You should still be able buy it secondhand from various stores, such as Amazon.co.jp ; but obviously you need to figure out how if you're not in Japan.
Edit: it seems two secondhand ones for sales don't have the poster. The "collector item" one does have the poster, though. Changed the link to direct to that. There is one (poster only) for sale on Suruga-ya, too.
Thanks ^^
E5a1b0t
Where can i find this? (Testament of Sister New Devil)
https://yande.re/post/show/305792/pierre_yoshio-shinmai_maou_no_testament-hasegawa_c
Was it some extra to a Special-Manga-Volume or an Anime-Magazine? And how coud i actually get it?