Hi, I run 3 DK's through icc HC every week and in mine, and most other players the best talents for tanking is blood. Frost tank with 1-handers can also be great for dungeon farming, but in general for raids you are gonna want to be blood spec.
This is the best spec in my opinion (double buff spec[AP & haste]): this means you don't need to run a frost DK in your raid also, because you have the haste buff:
https://www.wowhead.com/wotlk/talent...1ts841s8g51sxd
Short explanation of the talents:
- You mainly want to get "will of the necropolis" talent. Very strong defensive talent.
- Rest of blood talents is focused on aqquiring the most important defensive talents with the most optimal talents for threat.
- Icy reach is great for a lot of fights, will allow you to make great use of chains of ice on valithria for example and allow you to icy touch mobs from a far distance if you want to have threat on them.
- Killing Machine & Glacier Rot is your main threat talents. These talents are the reason DK's is the number 1 single target threat tank in the game.
- Frigid Dreadplate is not a good talent, it gives you avoidance which generally is considered a less important stat on tank as it isn't something that you can count on. It also doesn't count as a dodge or parry so it won't even proc runestrike.
- "Virulence" from the unholy tree is extremely good. With t10 and armor items you hit will not be optimal. Usually you go for 8% melee hit, which means you are not hit capped for spells. I personally don't like to miss Icy touches as it can mess with my rotation
GLYPHS:
- Dark command: you dont want to miss taunt
- Disease: you generally dont like to waste runes on plaguestrike, this glyph helps with that
- Vampiric blood: There is nothing better, extending this defensive cooldown can in some cases save your life, as it also increases the healing you get from rune tap and deathstrike