Magicka DK is a decently strong class, but it is generally forced into a tanky archetype. This is down to DKs not having the means to run light as safely that other classes have, such as cloak, shields, or very high healing, DKs passives all show block to be its niche. On top of that, they are a slow class overall (Not a bad thing, if done well.) which makes them susceptible to damage even further, a while back, DKs had skills that could aid in this, but now they have been gutted a little. Hell, they even nerfed them in HOTR with the burning passive losing 16% damage. (Buffed all around, but no reason to nerf it for DKs.)
The way I see DKs is as a slow offensive class, with sorc being fast offensive and templar being slow defensive for reference. The darth vader from rouge one style, blocking and reflecting attacks as they get closer. Oh wait, they snipped the wings.

This brings me to what I think needs fixing, as you can tell by the title, skills.
Dragon leap: This is a good burst skill, but is there any reason that it should continue to have its range nerfed even though the leap2keep is fixed? I think not. The shield is an OK addition, but not really needed since it should be a pure offensive attack, there is much better if you are looking for defense. Possible change: Unavoidable CC. Similar to fossilize it can push everyone back. Definite change: Increase range
Reflect: Whooo boyy. *** whoever *** this skill out of existence, hurting light DKs hard. 4k mag for 4 projectiles* for 4 seconds. Cloak or streak can make some abilities completely useless, being untargetable/far from the attack. What can wings do? Waste ur fucken time. Fix: Make it a non timed 4 projectiles. ALL PROJECTILES. Sorcbad's spammable doesn't get a pass.
*Terms and conditions apply
Stonefist and Chains: Stonefist is just a niche version of fossilize, either morph is some small resistances, or a silly heal. It has maybe one solid use for heavy attack DKs due to it range, but it is blockable. Fix: Rename this ability to tectonics, make this chains replacement. Then fix chains into a worth while gap closer (Chains is split between a useful tanking ability and a gap closer, however it has some major height issues associated with it.) Or maybe even ditch chains all together, and make a new ability, we survived without chains being a useful gap close for long enough.
Inferno: Another ability totally gutted, used to be AoE, but it isn't anymore, for reasons unknown. Its just a shitball atm. Its OK in 1v1/1v2 but its too unreliable. And the heal morph is literally the most useless skill I have ever seen. 5k heal every 5 seconds, but not you. Utterly unreliable. Make them AoE. Make the damage type, and the heal based of highest stats. Either poison/fire. Make FoO, consuming inferno, that gives either major magicka steal or major stam steal. Make the heal morph give constant health to you and allies around you based of the enemies within the AoE.
Finally...Take this with a grain of salt...
Execute: DKs are the class with the least burst, they rely on dots to wear an enemy away, but the enemy can purge or heal those dots in 2 buttons. And having no execute, it is harder to kill enemies, especially moving enemies on a DK. This is why I feel that DK should get the implosion passive in the form of cremation/Intoxication. Who better than a dot heavy class without an execute to receive the passive. It would start at 25% instead of 15% but become stronger the further down you go, and have the same chance it does now.
These wont make MDK much stronger PVE wise either as most of the abilities bar inferno aren't used in PvE as a DD. And the inferno change wouldn't make it more damaging, only more reliable. The execute change will provide some extra damage, but not enough to make or break bis, as stam will still be better.
Thoughts?