3 runes that are without a doubt undertuned, but also have no place in the game

Iron Skin, Mirror Shell, and Legend: Bloodline

3 armor/mr and +5% (conditionally) isn't the kind of high impact choice we were promised from Runes Reforged. Personally I don't think it would feel good when tuned competitively though. Picking either armor or MR based on the lane matchup is the least exciting choice I can imagine. Either you are forced to take it to deal with a hard matchup, or you take it to double down on your advantage in an easy matchup. Either way you're choosing passive sustained durability, the most boring possible choice. I don't like these two runes regardless of the numbers on them.

Bloodline maxes out at 6% lifesteal with current PBE numbers. It's the only Legend rune without a base value. I don't think I'd take it on any champion with these numbers. Just like IS/MS I don't think it's a well designed rune. Lifesteal is abundant on items, but adding it from runes gives you too much item flexibility. So I can see why it's so undertuned. Nobody's going to use it. It would be better to replace it with something totally different.

So I think these 3 runes have no place in the game. With their current numbers nobody will use them. With higher numbers they will have negative effects on the game.