Not specifically related to Series 11, but I'm just now noticing that Akira Fujikawa recently started posting albums of their FE Cipher illustrations on Pixiv, many of which were never shared before. Here are links to the relevant albums and which character cards are featured in each of them:
Series 10
Leif R, Forrest HN
Series 9
Alm N, Gray N (both previously released on Twitter)
Series 8
Tharja R, Tharja N (same as Alm and Gray)
Series 1~7
S1: Marth N, Ogma ST
S2: Forrest R, Forrest N
S3: Priam HN, Greil ST
S6: Claude HN, Forrest HN
S7: Hisame HN, Hisame N
They also contributed the art for the new Xander and Ryoma in Series 11, but have not posted them anywhere yet at this time.
This illustrator seems to sometimes also be credited as Shoko Fujikawa, but I don't believe this correct and is meant to be spelled in English as Akira Fujikawa according to FE Heroes (for Celica).
May any of this information be interesting or useful!