In 0.77 the only full armor set I know of is the champion plate armor. In a later version of the game I would like to see more full armor sets, ones that you dont just buy from the shop and provide a complete set bonus.  I know that you can find champion armor but it seems a little unrealistic to expect to complete the set that way, especially as new items are added. Ive only ever gotten 1 of the set myself per game(helmet/boots/chest).

To make it possible to complete armor sets I would suggest increasing the likelyhood of finding a piece as loot if your champion is carrying another of that set. Also the sellable monster parts seems to set up for a crafting system. A possible crafting system could be that once you have unlocked enchanting/blacksmithing you could create armor pieces and weapons from a new part of the shop (blacksmith window). You could make things like spider silk armor/venemous dagger, ogre leather armor/brutal maul, drake scale armor/shield, elemental plate/weapons (shrills/elementals). Animate armor/sword (golems).

The important thing is too balance it so that you dont need a full set but might want to put better individual armor pieces off for a while if you have a complementary set.

*On a somewhat related note I strongly believe we need more armor classes, like splint, studded and half plate, not just for champions but regular troops.