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Is that all for this topic... it's a bit sparse. And where is the Mage's Ring...
Let's discuss the combined artifacts and submit some suggestions.
1. Sniper's Bow is good when you have an army of several thousand Liches. If, for example, some creature (like a dragon) flies toward my Titan, I cast Clone on the Titan (Teleport is an option but it costs mana), then the "real" Titan waits while the cloned one attacks, ideally with ranged attacks, or at worst with a sword. If I'm lucky, I can take it down in one go and keep the clone. The Sniper's Bow takes up three slots. For example, the Elixir of Life and Shackles of War cannot be used together.
2. Titan's Thunder is a good artifact. At the start of the game, the lightning strike saves you from spending mana. It's also very convenient because it leaves the feet (Speed Boots) and hands (gloves) free for hero movement speed, plus another hand slot for whatever you want, including the Elixir of Life.
3. Cursed Armor. Good, but the primary skill increases are too low. Good for defending a Castle or attacking neutrals. Plus, it occupies primary slots.
4. Might of the Father of Dragons. Good for Barbarians and warriors with weak magic. By the time you assemble the artifact, the game is almost over. It occupies practically all slots except the bag, and there's little point. Level 4 spells are Resurrection, Berserk, etc. Without them, the game isn't the same. My rating: 3 out of 5.
5. Admiral's Hat. Put on the hat - get on the ship, sail, get off the ship, take off the hat, and that's it. A convenient and useful artifact, although you could use Water Walking magic or Levitation Boots — within reasonable limits, of course. My rating: 5 out of 5.
6. Elixir of Life. Nothing bad to say, everything is great. Only that APPARENTLY creatures don't regenerate without a tent. Hard to assemble because rings are everywhere but you can't find the "flask". My rating: 5 out of 5.
7. Legion Statue. Super artifact. Especially considering that growth increases in all towns. Very hard to assemble, and usually by the end of the game when it's basically no longer needed. My rating: 4 out of 5.
8. Horn of Plenty. Cool artifact. 4 of each resource (except wood and ore) per day. Resources can later be exchanged for gold or used to buy artifacts. Not very hard to assemble. My rating: 4 out of 5.
9. Cloak of the Undead King. The best artifact in my opinion, and unfair at the same time. More than once I had a level 25 hero, and when I found this artifact, I immediately switched the main hero to a Necromancer and built them up in 3-4 weeks. For example, on the Krauwind map, I effortlessly had 25k X 8 slots = 200k Liches. And it's unfair because it's invincible... My rating: 5 out of 5.
10. Angel Alliance. No comments. The coolest artifact in the game, after the Cloak of the Undead King. Though it takes up many slots and is a pain to assemble.
My rating: 5 out of 5.
11. Mage's Ring. Practically a useless artifact. I don't even want to talk about it. Rating: 1 out of 5.
The descriptions of the artifacts are based on my personal playstyle. Of course, your tactics may be completely different and consequently the use of artifacts will differ.
Added after 13 minutes
Here are some suggestions.
1. There are 3 bags of gold in the game, roughly for 250, 500, and 1000 gold per day. Devs - you should make it so they can be combined into an artifact giving 5000 gold per day.
2. Horn of Plenty. Include a wood and ore cart/wagon in it and add 4 of all resources per day. (maybe 5).
3. Diplomacy artifacts. There is a ring, a cloak, and a medal - why not make it a combined set? Reward: free retreat and 25% joining of weak neutral armies for 25(50)% cost.
3. There is a Cloak of Speed, Necklace of Speed, and Ring of Speed. Combine them and the reward is: all units move first with a +3 increase to creature speed. You could also invent some other artifact, like a Hat of Speed, to increase the assembly difficulty.
4. Spell Resistance. Boots, cloak, pendant (necklace), add (invent a new artifact) and the reward is 75% resistance to magic of all levels.
5. Spheres of Water, Fire, Air, and Earth. Try finding and collecting them. Reward: 100% increase in elemental damage. And if you collect all the spell books, then +15 to Knowledge and Spell Power (or something else).
I wrote everything I remembered. People, if you have suggestions or wishes, please add them.