Basically, people are voting for the 5th game, and I'm not against it; the main thing is that Niival doesn't make it too difficult.

We'll create a poker-style deck with 54 cards.

Next... I'm not very familiar with the 5th game, but as I understand it, there are 8 factions. Accordingly, there are three options:
1) We can create two decks, each with 4 factions, and include creatures with upgrades.
2) We can create one deck. With 2 factions per suit, without upgrades, including all creatures. Here, we can draw an analogy: evil faction with evil, good with good, neutral with neutral...
example: humans + elves = diamonds.
3) We can create one deck, limiting ourselves to four factions with upgrades.
example: humans = diamonds; Necropolis = clubs, etc.

I personally lean towards the 2nd option, as it allows us to include all monsters and factions in one deck, which, in my opinion, would be more appropriate.

Write which option you like best and describe which suit you think should be assigned to which faction.

Added after 46 minutes
Here's an even more detailed version of what a card might look like...