A guide on how to add this game from Epic Game to Steam.
How to Add It from Epic to Steam
You have to buy it again to get it on steam.
What you can do, is add the game onto the list (you can add non-steam games) you can´t access anything on steam with it ofc (workshop, achievements, etc) but you can showcase others you play a nonsteam game. You can even custom name it like:
Watered Down Grand Strategy Game
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