I don't use all of these abilities, but perhaps the most overpowered combo in here is Reflective Scales + Standard of Might + Impulse spam, which is my DK's bread and butter. These abilities shouldn't lose their functionality, but be balanced in relation to comparable spells. Impulse and Whirling Blades shouldn't outstrip every other aoe, for example.

I posted this in a reply below, but I'll put it up here so it's seen: I know 1.6 is addressing many of these abilities. However, 1.6 is not out yet. Player input matters. Whether you agree or disagree with the planned changes of 1.6, your opinion doesn't matter until Zenimax actually hears it. I agree that there should be nerfs, but not how Zenimax has, or plans, to implement those nerfs. So I'm posting my opinion!

Bolt Escape: The "bubble hearth" of ESO. It's been nerfed once, already, but the nerf was ineffectual. Any Sorc with a mana pot can escape the field of battle in seconds, mid-combat. It's bull that they can move fast enough to get away from mounted players, with enough spare time leftover to stealth. If it's overpowered to survive large groups with defensive abilities, it's just as overpowered to survive through mobility.

The Solution Diminishing returns. Each use of bolt escape, within 'x' seconds after the first, covers less ground. Also, remove the first nerf of bolt escape. Since it eats at the sorcerers mana, it actually disincentives turning around and fighting. That way they can use Bolt Escape to get out of AoE, siege, etc. They can't, however, fly across the map. Additionally, they can still fight after using Bolt Escape, encouraging real pvp.

Standard of Might My standard is overpowered because I can use it non-stop. This is addressed in 1.6, with the upcoming changes to ultimate gain. As it stands, however, DK's under fire from multiple enemies can drop their standard back to back. Using Vet Wayrest as an example, I can drop my standard of might every time the nightmare bats spawn. While I'm healing. That's insane. It's arguably the best ultimate in the game, so there's no reason we should be able to use it consecutively.

The Solution Changes to the ultimate gain in 1.6 are a better solution than anything I came up with. Just posting my support of those changes.

Veil of Blades A rival to Standard of Might, it's overpowered for the same reason. It can be used consecutively in combat, as attested to by my Nightblade guildmates.

The Solution Changes to the ultimate gain in 1.6 are a better solution than anything I came up with. Just posting my support of those changes.

Reflective Scales I doubt this one needs an explanation, but here we go: three dk's can hold back two full groups, relying primarily on reflective scales and CC (to keep enemies from getting into melee). It's cheap and a mana-build DK can pop their Scales consecutively; when used correctly, one's sure to live as long as they have reflective scales up.

The Solution Attackers still take full damage, but the Dragon Knight takes a portion of the damage too. For example, a Sorcerer strikes a Reflective Scales Dragon Knight with Crystal Shards. The Sorcerer takes 100% of the damage they would have dealt, but the Dragon Knight also takes 25% of the damage they would have received. Couple this with diminishing returns: if a DK uses reflective scales a second time, 50% of the damage reaches the dk. If used a third time, 75% of the damage hits the DK. That way, reflective scales serves its purpose, but doesn't guarantee the DK's survival.

Blazing Shield Blazing Shield is for PvE what Reflective Scales is to PvP. In my guild, most Templars build their specialization around blazing shield. With blazing shield, Templars just need aggro. The more mobs attacking them, the stronger the shield, and the more damage it returns. The only content that a couple Blazing Shield Templars can't do unassisted is a group dungeons and pvp.

The Solution Edit: Cap the bubble at 62%% of the player's HP. It wouldn't get any more powerful beyond the 8th mob.

Impulse Again, does this really need an explanation? It's by far the best aoe when considering both cost and damage dealt, plus it reduces total health of every target affected. Impulse spam has become a taboo in pvp... not that it's stopped people from abusing the spell.

The Solution Instead of dealing burst damage, turn impulse into a short duration DoT ability. Say, 3-6 seconds long. Allow the dot to stack up to 'x,' and no further, resetting the duration with each new application. Equate the health reduction's duration with the DoT's duration. Finally, 'x' stacks is the maximum a single player can receive at a time, no matter how many enemies are using impulse. No longer could groups spam impulse exclusively. Instead, they'd supplement Impulse with other aoe abilities. In turn, the need for other AoE abilities costs ability slots otherwise used for survivability, or crowd control.

Whirling Blades Sharing Impulse's propensity for spamming, this could use a small nerf. Though Whirling Blades doesn't do excessive damage, it pays for itself and then some.

The Solution Reduce the player's Whirling Blade damage for the duration of the stam regeneration, and compress the stam regeneration (perhaps 20 stam every 1 second for 5 seconds). Maybe buff the abilities raw damage, though, so that it's still worth using every 5 seconds. Just needs to change so that it's not viable by itself. After all, it's one of only two aoes that are viable without supplementary abilities.

Siphoning Skill Tree This is a bit different from the others, because I'm not targeting a specific ability. Groups of Siphoning Nightblades can substitute the need for healers entirely, while still dpsing. This means that those groups can do more damage than any group that needs a healer in their midst.

The Solution Diminishing returns. If a player is being healed by Soul Siphon or Funnel Health already, healing from another Soul Siphon or Funnel Health is reduced significantly. That way, every group needs designated healers; no more homogeneous Siphoning Nightblade groups.

Edit:

Jumping Abilities Looking at you, Dragon Leap and Ambush. Because these abilities go vertically as well as horizontally, players can clear the pvp gates without actually opening it. Get a group of nightblades and/or dragonknights together, and you can get a large group past the gate without taking any keeps.

Solution Put a height cap on ambush and dragon leap, one that's below the second floor of the gates in pvp.