Shiv of Lunari
According to what Riot Games advertised, Dark Items are supposed to be a more powerful version of regular items. They may have forgotten about the Shiv of Lunari because it is far too weak compared to the Iron Solari. In the early game, the large shield from Iron Solari is significantly stronger than the armor/magic resistance provided by the Dark version. This effect will help your frontline champions, whether low or high level, become much sturdier.
Furthermore, the Shiv of Lunari has an extremely “nerfing” effect that makes the champion equipped and their allies receive less energy when attacking normally. Remember that this item is often used on frontline units, those champions with crucial crowd control skills. If you equip the Shiv of Lunari, it means those skills will be unleashed more slowly than usual. This is no different than causing players to lose rounds faster.
Rageblade
With the Immortal Shieldbow being an extremely powerful item, there were high hopes that its Dark version would also become a dominant item. However, Rageblade brings none of the power of Immortal Shieldbow, if not a worse version. The strength of Immortal Shieldbow comes from helping champions deal extra damage when they take hits. However, this damage amplification effect is completely absent in Rageblade.
The effect of Rageblade is to enhance attacks every 4 seconds based on the damage received. This requires the equipped champion to have a tremendous amount of “tankiness” to maximize the effectiveness of this item. Unfortunately, the champion pool in Teamfight Tactics Season 5 lacks any unit that meets this condition at a 2-star level. This item may only be suitable for a 3-star Mordekaiser (a 4-cost champion), which is a very rare occurrence.
Scrappy Armor
When mentioning Thornmail, we think of the damage reflection ability of this item. However, its Dark version, Scrappy Armor, does not possess the aforementioned damage reflection effect at all. In fact, this item also lacks the ability to reduce critical damage and only provides 200 armor. Essentially, Scrappy Armor only offers a large amount of armor but does not provide any sufficiently strong defensive effects.
As a result, this item has become incredibly “useless” in the current meta dominated by magic damage. The number 200 armor sounds strong, but it means nothing against Karma’s Incinerate or LeBlanc’s Chains of Command. Even when facing strong physical carries like Draven or Aphelios, the lack of critical damage reduction effects also makes champions using Scrappy Armor extremely weak. In summary, you should not equip this item.