Hello my fellow cub
On Guardians, there are 2 basic builds - one defensive (NoW) and one hybrid one (UFR).
The first one is more used for Raid progress, the second one is better in M+.
NoW legendary has nice synergy with Survival of the Fittest talent + Barskin Conduit.
UFR has brutal synergy with Earthwarden and Incarnate talent (it will even protect you from Necrotic affix - you will get these stacks, but with Incarnate, you will protect yourself with massive absorb shields so, thats why it is insane ).
As for Soulbinds, I pref. Niya over Korayn (Korayn is sort of trap soulbind - Hold The Line is really bad conduit, because you just cant stand on one place for 4 seconds and you lost second Endurance conduit for 1 Finesse, which really s**ks. Only one build, which is relatively good with Korayn is with First Strike conduit - you get 2x Endurance, 1x Finesse and 1x Potency conduits).
Guardians need more dps, and Niya has nice conduits (2x + 1x +1x) with Niya´s Tools: Burrs - it does about 5% dmg overall for me. Its nice mix of everything .
Dreamweaver is really good soulbind, you can get 3x Endurance, which is insane for Guardians and Field of Blossom (which is really insane in M+ with UFR build and then Incarnate - literally 60-70% haste with all things up for 20 seconds ). But, there is one VERY BIG ´BUT´. Dreamweaver is really bad with Pod conduit, because if you get killed, you will loose agro on everything, you cant do anything and you can´t be Battleressed. Your whole party will die because of that (In raids, its the opposite, because there is second tank everytime so. But, for M+ Dreamweaver is nasty trap for tanks).
I hope that this will help you a bit