>>504796308not hard until you get to m+/raiding where you have to worry more about things like kiting, interrupts, tankbusters, and tankswaps.
blood DK is..how to put this...its the resto shaman of tanks. it has a very big kit with a lot of tools, it can break or ignore a lot of status effects, has multiple interrupts and stuns, aoe pulse damage, ground based damage, and DOT damage which also leeches, it has all purpose mitigation, but also a lot of magic mitigation, buckets of self sustain, a combat rez, and some of the most tank cooldowns of any tank spec. the 2 hardest parts to playing blood DK are knowing how to pool runic power and use it appropriately for healing instead of just spending it as soon as you get it, and knowing and how and when to rotate your tank cooldowns.
probably blood DKs biggest downside is that it doesnt have a lot of mobility, so it can struggle on fights that require frequent long distance or high speed movement or kiting, although it does have access to good slows.
it is also a tank that is going to spend a lot of time in the 25-40% health range. it takes some getting used to, and newer players can panic when it happens, but blood has an extraordinary amount of passive effects that kick in at low health, such as a flat 35% damage reduction below 30% health, which is the equivalent of a permanent strong tank cooldown at that threshold. you also have blood draw and purgatory which can serve as safety net mechanics so the fight isnt always over when you would take a fatal hit.
the 2 biggest mistakes i see for new blood DK players are holding on to dancing rune weapon and especially vampiric blood too long. with red thirst, vampiric bloods effective cooldown is like 30 seconds, and its duration can be talented to 14 seconds, meaning you can have near 50% uptime on that skill. dancing rune weapon similarly gets a ton of cooldown reduction thanks to insatiable blade, which can be further sped up manually by tombstone.
