Yrden, Scorch, don't pass vs Eredin until leader ability is used.... There are 3 ways to win right there. Black Blood works too I guess. Uh... Shupe? Pitfall trap and a crystal ball? Schirru? Vrihedd Brigade and Brouver charges? So, 8 ways and a crystal ball to handle it?
Slyzard doesn't need nerfed. The issue is Immune shouldn't be on a leader. On an orders card, eh, arguably alright. I don't like the concept at all because I remember Promote. It's probably not going to go. Pointing out the potential of abuse from putting Immune on a leader is the next best thing . Even that probably won't get considered.....
4 out of 5 times, it is killed before it does any damage and in other times, there are no DW targets. I am not good in MO and it contributes to that issue, netherless Slyzard is much much OK than so many other broken cards.
[Like WTF (W = Why) is Archepores both Thrive and DW and why would anyone not include it in their deck?]
I'd only point out that unless there is a Ruehin (already nerfed) on a row (any lock counters..), Slyzard (with Eredin) doesn't produce any points, he just prevents control cards from dealing points, so you can just do more points than the opponent does (Slyzard itself contributes only 4 power all this time, it doesn't change) to win a round, and keep Control for another round..
There are plenty of cards that can attack an immune enemy, such as various weathers and row effects (Lacerate, Traps)
If you don't use Scorch directly, you can use any card that creates a Scorch or Geralt: Igni
If Slyzard is freshly created using this amazing Wild Hunt mage whose name I can't remember, you can kick this mage to another row using Brouver's charge and kill 4hp Slyzard using a 4-provision pts Elf who's got 1hp and auto attack for 4dmg