The Frost Death Knight receives a tier set that's thematically fun and exciting that primarily sees an AoE gain. The single target boost by equipping both the 2p and 4p is around 3%, with AoE going up to 8-12%. The set provides some passive damage increase to
Howling Blast and
Frost Fever as well as a CDR to
Frostwyrm's Fury. This is quite interesting as this is a talent quite far down into the tree. One has to pick it up to gain any of this value. The 4p send a full-strength
Frostwyrm's Fury whenever you've used up 15
Rime. I must say that I like the idea of more dragons, however the prospect of ninja-pulling trash in Mythic+ does not entice me. It has the same hitbox as
Frostwhelp's Aid, extending a whopping 40 yards in front of you. Given that ninja-pulling with
Frostwhelp's Aid already happens frequently (I'm guilty of this as well I'm afraid), getting a
Frostwyrm's Fury when you're just pressing your
Howling Blast is bound to pull even more. Sure, one can easily track the buff so that you're ready for when it triggers. Still, it is bound to ninja pull even more...
I believe an easy fix would be to attach the
Frostwyrm's Fury to some other spell. For instance, if the tier set said something like "consuming 15 procs of Rime empowers your next Pillar of Frost, unleashing a Frostwyrm at 100% effectiveness when you press the ability". This would gives us far more control, and wouldn't make us more prone to ninja pulling than we already is! This also resolves issues around holding on to your procs. If a big add wave is coming up, you'll want to avoid consuming your
Rime procs to unleash the Frostwyrm on the adds. This will cause detrimental gameplay where you'll be avoiding a significant part of your rotation to optimise the tier set.
I do feel the weakness of the set in single target must be addressed as well. As it stands, simply holding on to your T29 set will be by far more powerful than swapping to the new one! I believe something more is required that isn't just the extra Frostwyrm's. If we continue on the attaching to
Pillar of Frost idea, it could increase the buff further whenever it's empowered for instance. I'm sure the devs can think about a lot of fun and interesting ways to make the set better in single target!
Overall, the Frost Death Knight tier is fun and exciting to use. Unfortunately, it's incredibly prone to ninja-pulling in Mythic+ and its single target power is far too weak.