Legendary weapons should have a concrete mod called:
TImeless Decay
It will allow you to semi-phase out of combat but not entirely and during that process you will be absorbing some very minor damage (not all the damage which means you can still be hit) and gaining slight buffers. During the phase animation, you will be unable to perform any actions at all. After the phase ends, your 2ndary skillset is made available but your main attacks will still be unavailable for some time.
This allows the character equipping legendary status to be able to move slightly more freely around the battlefield, as a slight escape tool, or for a more minor offensive where for example a warrior could absorb some more damage and close the distance between him and the ranger while still having access to his skillslots in order to close even more distance, while absorbing a little bit more damage. His main attacks during and after the absorb will still be unable to connect though, therefore he would be relying on his skillsets to control until his main attacks become available again.
This is pretty balanced, and is pretty metrical in nature since he would be sacrificing his main attacks and only have access to his 2ndaries. If he were able to still attack after the phase animation ends while absorbing damage that would obviously be a direct conflict of interest since he would pretty much just be absorbing damage. But since he is absorbing damage and then sacrificing his main attack, he is then relying on his control skills to gain more footing. This counterplay of absorbing damage, while not being able to dish out any especially a short while even after the animation has ended (which is important because if it were only during the phase then he could merely use it as a gap-closer which would be OP) is perfectly balanced. Thus this special legendary technique can also be used as an offensive “time-staller.”
As an escape tool, you will still be unable to escape too effectively, because your action bars will be locked out. All you will be doing is running and absorbing a little damage.
Note that this shouldn’t be a separate skill in and of itself, but it should be only for legendaries.
Edit: Also, the more you use this skill, the more it drains your Legendary Weapon’s energy bar, after it is completely drained it will require a small fee to recharge. This acts as the third gold sink source.
This makes elite players have to consider how to manage their funds while still being able to contract Timeless Decay. Since players with Legendaries will usually be rich anyhow but still have to make back the small fee through this final gold sink.
Purist, Idealist, and Theorist.