Part one.

During the assault on Blackrock Spire in the Second War, Mograine of the Silver Hand witnessed an orcish warlock channeling magic through a dark orb. After the warlock's death, Mograine went to claim it for the Alliance, but his hand was badly mangled as soon as he touched it. Though describing the orb as the "living embodiment of shadow," he was still curious as to what power it might hold and kept it in an iron chest.

Mograine kept the orb a secret until the Scourge reached Lordaeron. He revealed it to several other members of the Silver Hand, suggesting that they search for the orb's polar opposite - a manifestation of the Light itself - to be used against the impending undead holocaust. Mograine's peers, appalled at the sight of this dark crystal, attempted to destroy it with a holy spell. Unexpectedly, the crystal absorbed the spell and became its antithesis, the very crystal of pure light that Mograine suggested moments before, and even restored life to his mangled hand. It was decided that from this crystal a weapon would be forged that would smite the undead with such power that only a cloud of ash would remain in its wake—The Ashbringer.
Source

The first part is the part of recovering the orb. Mograine enters the Blackrock Mountain, finds cultists that syphon the orb, kill them and take it. He then shows the orb to Order of the Silver Hand. Some generals don’t like the idea, some do. They argue and Mograine forms Scarlet Crusade. Few generals follow him and they break from the Order of the Silver Hand. Mograine asks Archmage Timolain to study the crystal. Archmage accepts and while he does it, they are getting attacked by the Scourge. Some break through to Timolain and he raises crystal in protection. The artifact burns them and turns them into ash. He says that he’ll forge a holy weapon, that will help Mograine fight the Scourge and leave only ashes – the Ashbringer. Archmage suggests that Magni can craft the sword and hands the crystal back. Crystal whispers Mograine that he shouldn't keep the mage alive as he knows too much and crusaders execute Timolain.
To sum it up, this part is turned into three different stages:
a)Recovering of the crystal.
b)Arguing between Mograine and generals.
c)Meeting of Mograine and Timolain.
This part will need following actors:

Highlord Alexandros Mograine – main role.
High General Abbendis – one of Mograine’s commanders.
High Inquisitor Issilien – liaison for the Order of the Silver Hand. Accompaying Mograine on his quest.
Highlord Tirion Fordring – commander of the Silver Hand. Argues with Mograine during the meeting.
Arcanist Doan – mage of the Kirin Tor, suggests while arguing that orb can be studied by Archmage Timolain.(Etanur)
Archmage Timolain – the one who studies the crystal. (Tergand)
Blackrock Warlock – he’s defending the crystal while Mograine kills him.
Few random orcs and knights of the silver hand – fightning each other during the crystal recover. Also knights follow Mograine during the arguing with generals.

Part two.

After the Silver Hand was dissolved following Arthas' betrayal, the remaining leaders banded together to fight the undead of the now-Plaguelands. Ashbringer became the most lethal weapon in their arsenal — so much so that it quickly garnered the attention of Kel'Thuzad. Balnazzar, in the newly possessed body of Grand Crusader Saidan Dathrohan, sought to secretly manipulate the remnants of the Silver Hand for the purposes of the Burning Legion. After Mograine stated his intentions to attack the Undercity, Balnazzar put plans into motion to eliminate the Highlord in order to protect his brother, Varimathras, who in turn was manipulating Sylvanas Windrunner and her Forsaken.

Balnazzar made a pact with Kel'Thuzad to eliminate the Highlord: the bane of the Scourge would be destroyed, and the dreadlords' agendas would continue. He corrupted Mograine's son, Renault, and made plans to set a trap for the Highlord. Renault led his father and High Inquisitor Fairbanks to Stratholme, where the legions of the Scourge awaited them. Renault fled and hid while Mograine and Fairbanks fended for themselves. Fairbanks eventually became trapped alive under a pile of corpses. Mograine alone continued to smite thousands of the undead with ease, but was eventually wearied and dropped his blade in fatigue. Renault came out of hiding to exploit his father's vulnerable state. He took up Ashbringer and slew his father, which simultaneously corrupted the blade by using it for such a treacherous act. Meanwhile, Kel'Thuzad resurrected Mograine as one of his death knights of Naxxramas and reclaimed his corrupted blade. Renault became Commander of the Scarlet Monastery, and Balnazzar gained complete authority over the Scarlet Crusade.
Source

The second part comes after a little break of 10-15 minutes. Probably, we’ll switch the place to another. The second part will happen ‘’one month’’ after first part and this is the part about death of Ashbringer. Mograine travels to Ironforge and Magni Bronzebeard himself crafts the blade. Mograine wears the blade as it slowly unleashes it's will at him. Alexandros becomes a living doom for Scourge, as he cleanses Tirisfal Glades, Western Plaguelands. A month passes and he reaches Stratholme. Meanwhile, Grand Crusader Dathrohan suggests Mograine’s son, Renault, to betray his father and promises him a commander’s place. Renault Mograine invites his father to join him in Stratholme. Alexandros agrees and him, Renault and Fairbanks, the priest of the Scarlet Crusade, go into the city. They reach Crusaders’ Square and get attacked by the Scourge. Mograine starts killing the Scourge but then he sees that Fairbanks and his son are in danger and he throws the blade to Renault, unsheating his usual sword and fightning undead. Renault catches the sword and drives it into Alexandros’ body, leaving it inside of the body. Renault runs to the gate and locks it, leaving Fairbanks inside the Stratholme. Renault enters the Tirisfal Monastery and proclaims himself a new Commander as Fairbanks enters and tells the story of Renault’s betrayal. Mograine says that Fairbanks is mad and orders to lock him in one of the prisons. Some people are surprised by the reaction of Mograine and demand answers. He denies and people break from the Scarlet Crusade. They form Argent Dawn and make base at Eastern Plaguelands. Grand Crusader Dathrohan makes new ranks and promotes in Tirisfal Monastery.
This part will come in different stages:
a)Killing Timolain.
b)Death of Alexandros.
c)Argent Dawn breaks from the Scarlet Crusade.

This part will need following actors:
Alexandros Mograine – main role.
Inquisitor Fairbanks – priest of the Scarlet Crusade. Informs of betrayal in stage c).
Renault Mograine – son of the Highlord. Betrayes him in stage b).
Brigitte Abbendis – daughter of High General Abbendis. Informs that her father went on the quest and made her new High General in stage c). Gets assigned by Dathrohan to Tyr’s hand.
Grand Crusader Dathrohan – possesed by Balnazzar. Asks Renault to kill his father in stage b).
Archmage Timolain – maker of the sword. Dies in stage a).(Tergand)
Taelan Fordring – son of Tirion. Joins the Scarlet Crusade in stage c) as Dathrohan makes him new Highlord of the Scarlet Crusade and sets him a base in Heartglen.

The original lore about Scarlet Crusade can be found in this source.

Soon the part with speeches will come.