I played 3 games with this list today. I haven't played in a few months, so I was a bit rusty on rules (game 1, forgetting that scryer could remove 3" from a charge really killed my Alpha strike -- failed a 9" charge with a 6 and rerolled to 5 ? ).
Overall, I had a ton of fun with it. Using the Eidolon to teleport and debuff while Alpha striking the big block of eels and King worked really well. Ionrach was neat for the +1 cast/unbind but all in all, I definitely feel that rerolls from Domhain or Fuethan would've given much greater results. I'm also toying with the idea of combining two of the Ishlaen into a unit of 6 for staying power. I got pendulum off once the entire day, only because my opponents waited to dispell it and let me cast everything else I wanted. I'm also toying with the idea of removing 2x3 Ishlaen for 1 spellweaver, 20 eternal guard, and a burning head (more games are necessary).
I haven't played in a few months, so forgetting a few rules really hurt me, with some practice - I really see this list doing mid-tier in competitive tournies. I'm just looking to end in the upper 50% at Adepticon 2019.