I dont think you need to buff the immortal’s stats directly.
In the past though, the immortal received some nerfs of its own in an effort to curb the rampant proxy robo battery play that was wreaking havoc.
I say now that the battery has received a much deserved nerf, we can revert those immortal nerfs. Bring its cost back down, or lower it even further. Its almost 300 minerals and 100 gas which is absurdly expensive. Revert to 250 or even lower it to 200 if we really wanna push it.
Alternatively maybe pair it with a prism cost decrease back to 200.
I also stated in an alternative post here:
That I believed part of the issue is that forcefield specifically is pretty rubbish as ravagers completely invalidate them. There were some good counter-points made though, but I feel it’s important to point out.