How can we connect the fifth installment with the previous games in the series?

You can transfer from the Blade to SoD, but not the other way around. The Blade is simply an earlier version. However, everything should work fine in Heroes. I would gladly create alternative versions, but it won't be possible. In the Blade, artifacts weren't collected either, which is why I chose the latest version. We will link them in every possible way. In principle, your maps can remain compatible with the Blade (as an alternative).