As someone who enjoys playing against AI4 from time to time, I'm slightly disappointed interest in AI4 farming has remained low even after the HP nerf. I know many long-time players may still suggest rushing into FG with a 15% winrate deck, but that is, in my opinion, boring, tedious, and can be expensive for a new player if you don't win any cards. Farming AI4 can provide rare cards and a steady supply of electrum. Plus, it's fun! FGs are only fun if you have a fully upped deck with a decent win rate. So here's something I made before the nerf, it works even better now, of course:
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4sa 4sa 4sa 4sa 4sa 4vh 4vj 4vj 4vj 4vj 4vj 4vj 52p 52p 55v 55v 590 590 590 590 590 5c2 5f6 5f6 5ie 5lb 5og 5og 5v1 61s 8pm
Yeah, it's another grabbow variant, but it's made to take advantage of AI4. It's a bit slow(11-17 TTW in most games), but AI4 is often low on CC, and even when it's not, shriekers can burrow until you need to pump out the damage. You can keep yourself alive quite a long time with heal, black hole (they almost always have quantum pillars!) and nightmare. Plague and Toadfish provide surprisingly effective CC in conjunction with Fog Shield preventing damage, and deflagration is best used to keep shields out of your way.
I find it wins between 50-60%, with a decent number of Elemental Masterys. Using upped pillars and graboids helps, supernovas do not. A weapon, particularly Vampire Stiletto, Arsenic, Discord, or Druidic Staff can help. (Titan, Pulverizer, and Eternity are bad in this deck. Trident could work with some changes) It doesn't usually hurt to replace a Black Hole with a Shard of Focus. (use with care after the recent nerf!)
A lot of people probably will question the inclusion of Immortal, but I actually find it quite useful. Don't like it? Change it!
Parallel universe could be fun.
Comments, thoughts, criticism, all welcome. Let's make the most of the HP nerf to AI4!