I’ve been doing runs with cryptid, ankh, and ectoplasm, combined with eternal Baron and mime. This seems to be the most promising run for ante 4 naneinf yet. This graph I will show below is the maximum power of the copies in the ghost deck. The bottom red line is the approximate copies of 1.5x to get to e308, while the top red line is the formula I used to see how many 1.5x copies I get from red seal steel kings.
https://www.desmos.com/calculator/vn38vlj5gt
On top of this, I will show my best recorded run, which is in the e150s because of not discovering the second eternal mime with showman initially.