NAF – New artifacts with unique properties.

We could introduce a new class of artifacts, something like ultra-relics. They would be obtained only from combining different artifacts, merging them into one.

In reality, these would be the true relics. When comparing to Heroes 3:
minor artifacts in H5 = treasures in H3
major artifacts in H5 = minor artifacts in H3
relics in H5 = major artifacts in H3
super relics = relics in H3

Relics in H3 (or super relics for H5) are artifacts that provide +4-6 to all stats. But we shouldn't overdo it; I think a reasonable limit would be top-tier artifacts like:
+6 to all stats;
+12 to one stat.