In Legion we saw the return of Magni Bronzebeard from his petrified state in Cataclysm, and with his return he has stated his closeness to the world soul/titan/entity known primarily as what we call Azeroth herself.
Short story we aided him in Legion and we gained insight on the Titans even more with his help and illdans, granted with a sword (What sword ?) buried deep in Silithus. Also in Legion we got a whisper about him from one of Nzoth’s minions saying “The King of Diamonds has been made a pawn”.
Now in BFA he is our main character for the Azerite/Nzoth section of BFA where he asks us to “Heal the woonds” or stop “Elements going crazy” until further into the expansion him and various key lore characters, including Wrathion and the Aspects along with the titanic constructs Mother from Uldir and Keeper Ra’den to stop the Old God N’zoth, ultimately we succeeded or rather we think we did. Azerite also made an apperance in Shadowlands but merely as a tool and not mentioned in name.
This is the last we have seen of Magni, however this is where my speculation kicks into maximum overdrive!
So between Cataclysm and Late WOD/Early Legion Magni was in communications with the Incarnates in particular Razagath, as she has stated she felt Deathwings demise so I believe she communed with Magni but disguised as something a kin to Azeroth but the knowledge she shared involved her needing aid and there will come a time he is needed and such a time did as a Sargaras sized sword came crashing down.
This incident releasing not blood of the world but a deep saturation of earthen deposits which over the many millenniums has been slammed with various magics and forces including primal energies along with the potentially mysterious powers of the mad titans fury. This was the gold and blue jackpot the Incarnates and Primalists desired but there was one thing missing a spokesperson, Magni was perfect as he like us players can be and will be manipulated along with various power hungry individuals like Kurrog Grimtotem who was one such character, however gaining traction during the Shadowlands and possibly taking over the Grimtotem and turning them into the Primalists initial rebellion recruits then Kaldorei breaking from Elune then more power hungry individuals. Now this can be argued with “Mother and Ra’den are loyal to the titans” and to that I say yes they are but they also are not, Mother can be corrupted and used to experiment on anything and Keeper Ra he is disposable.
Now the Heart of Azeroth, this item came to use out of no where to which I suspect thats because Magni was informed where to go but the Chamber in question is actually a chamber deep under or close to The Dragon Isles under or either under the Isles under the Vault of the Incarnates or Tyrhold and not under Silithus as we wish to have been believed.
But Magni at some point during Shadowlands found he was being played and used eventually however at this point it was too late as he was either taken by the Primalists and is their key to tool to lure the Bronzebeards out to the Isles or a bargain to swap Magni for Khadgar or to bait Khadgar and any of the Aspects into a trap at a truly key moment or my worst scenario he is being kept to be sacrificed/eaten by oneof the major Incarnates to empower them.
Or I have been going on a tangent to find Magni has a role at a later story thread, either way I hope you enjoyed my potential story theory of Magni’s Servitude!