Yes, none of these sees play competitively speaking.
If you can, try to hold onto Oblivitron and Nithogg, as they're Standard and it'll only rotate next year, and who knows if they become playable, unlikely as it may be, unless you really need the extra 800 dust for something.
Most of these are generally pretty safe disenchants. The only one here I would keep is Dollmaster Dorian; due to Bloodbloom's impending nerf, there's a decent chance that Dorian will become the only way to make mecha'thun warlock work. Outside of that, while some of these have niche uses (like Arugal in the occasional pocket galaxy mage), they're generally not worth keeping around if competitive laddering is your main objective.
Having said that, this advice only really holds up for the wild format. I'm not very well-versed in the standard meta these days, so I'm going to let someone more qualified give advice on the legendaries that are still legal there.
Guy im thinking of disenchanting these legendaries are they safe to disenchant?
Ixlid fungal lord
Tyrantus
Halazzi the lynx
Oblivitron
Archmage arugal
The glass knight
Prince liam
Kangor endless army
Lady in white
Bwonsamdi the dead
Temporus
Princess talanji
Face collector
Captain Hooktusk
Nithogg
Dr.morrigan
Blackhowl gunspire(warrior tower minion)
Dollmaster dorian
Countess ashmore
Yes, none of these sees play competitively speaking.
If you can, try to hold onto Oblivitron and Nithogg, as they're Standard and it'll only rotate next year, and who knows if they become playable, unlikely as it may be, unless you really need the extra 800 dust for something.
Kangor's very occasionally sees use, but it's the most fringe one on the list I could think of. Definitely safe disenchants.
Most of these are generally pretty safe disenchants. The only one here I would keep is Dollmaster Dorian; due to Bloodbloom's impending nerf, there's a decent chance that Dorian will become the only way to make mecha'thun warlock work. Outside of that, while some of these have niche uses (like Arugal in the occasional pocket galaxy mage), they're generally not worth keeping around if competitive laddering is your main objective.
Having said that, this advice only really holds up for the wild format. I'm not very well-versed in the standard meta these days, so I'm going to let someone more qualified give advice on the legendaries that are still legal there.
Dollmaster dorian seems like a card that could do dirty things. I, personally would hold on to that one.
WAIT! The Devs said that the new mode will use old cards! So wait until they announce what it's all about if you don't need the dust right now
Never disenchant unless you really want/need something (and the ones on your crafting list can definitely wait)