Avizandum (Known to the Humans as Thunder) was an Arch Dragon of the Sky and the King of the Dragons before being killed by Harrow and Viren in revenge for killing Sarai. He was the late father of Azymondias and spouse/mate of Zubiea.
Powers and Abilties
Flight
As a dragon Avizandum had the ability to fly.
Electrokeneises
As a Sky Dragon, Avizandum had the ability to channel lightning through his body, He could also shoot it from his mouth.
Fireproof
Avizandum is shown to have the ability to withstand fire dispite his primal source being the Sky instead of the Sun as
he was able the guard the Border located in the Volcanic regions for centuries.
Temeprature Restiance
Avizandum was also immune to the cold as shown in the flashback of Heart of a Titan as
he had no problem breaking free from a wave of ice Viren Trapped him in and showed no signs of even minor injuires.
Biography
300 years ago
300 years ago, Avizandum Succeded Luna Tenebres as Monarch of the dragons. He personally stood guard at the border for most his regin. He killed any humans who dared to tresspass into Xadia. Know human ever knew his true name so they nicknamed him "Thunder", as his voice shook the ground whenever they spoke. He also imprisoned Aaravos in a magic mirror.
9 years before Book One
Avizandum appears in the flashback in the episode Heart of the Titan
when he finds a deceased Magma Titan with it's heart stolen. Rezaling that humans had tresspassed into Xadia and
killed the creature He then tracks down Harrow and his expidetion party as they were the ones who tresspassed and killed the Magma Titan to kill them in revenge for their tresspassing and murder. However Harrow, Viren along with a portion of their party manged to make it out alive.
Unfourtantley Queen Sarai was among the fallen. Her death causes Harrow to deem Avizandum his archnemises.
Death
Harrow originally put his hatred towards Avizandum aside for the sake of his sons
but 4 months before the events of "Echos of Thunder", Viren manipulates Harrow into givening in to his desire to kill Avizandum in revenge
for killing Sarai by connvincing him that its what she'd want. Harrow then allows Viren to use Dark Magic to enchant Sarai's spear into
the "Ultament Weapon of Vengence", The pair then part for The Border only for Avizandum not to show up show they go a few day long journey to the Sky Dragon's Place where Avizadum greets them with hostilty but becuase he's in a mercful mood that day since he deems this day a speical day, he agree's to let Harrow and Viren off the hook for their tresspassing but only if they agree to do it instantly, However Harrow and Viren refuse
do so since they dead-set on revenge for what Avizandum did to Sarai and the rest of the members who Harrow's expidention who also perished nine years prior to a lesser extent. Harrow acknowleges this as the reason for his a Viren's defence by reminding him that he didn't give
Sarai that chance. As punishemnt for their defiance, Avizandum attempts to strike his human foes with a death-blow for each of them, but Viren uses his staff to restrains Avizandum long enough to buy Harrow enough time to strike Avizandum with Sarai's magic enchanced spear.
Even though Avizadum had recently broke free of Viren's restraints it was already too late for him becuase the Archdragon broke free from them too soon. The spear then kills Avizandum by turning him to stone but not before Sarai's voice screams "Nooooooooo!" confirming once more that killing Avizandum was not somthing she'd want dispite him being her killer. As soon as Avizandum is killed, Viren hesitates before departing the Storm Spire with Harrow as he realized that the reason why Avizadum was in a mercful mood that day was becuase he sired an egg thus, was going to has a hatchling. He then convinces Harrow to let him destory the unhatched Azymondias as Viren was afraid that Azymonidas would grow up to become vengeful enough to turn evil by wiping out humanity in cold blood for what he and Harrow did to his father and convicnes Harrow that his fear about the full grown Azymondias was well founded, promting his friend to agree but out of reluctance as Harrow still thought killing an innocent baby dragon wrong even if they grew up to become a dangerous misanthrophobe. Harrow merely tolerated Viren's decison to "kill" Azymondias becuase he thought it was the only way to protect the human kingdoms from the future king's wrath.
Legacy.
Four months later Azymondias (who was saved by Team Zym) spots his father's stone corpse and distrubed by the sight
since he knew that the stone corpse used to be his father and knew the concept of death dispte only being alive for a few weeks
since Sky Dragon infants have a better understanding of the world around them than a human infant would. He is then conforted by Callum
who later reveals to share his late Step-father's hatred for Zym's late father for what he did to Sarai as she wasn't only Harrow's wife but
Callum's (and Ezran's) mother. However Callum can't decede weather he should feel happy about Avizandum's demise even though it avenged
the death of his mother or sad for Zym who lost a parent before they had a chance to meet. Rayla reassures
Callum that they'll break the cycle of hatred between their Kingdoms before heading to the Storm Spire.