Why did Malorne have 81 Attack?

81 updates.txt

We know that after each outermost Phase, the following Steps run:
-Aura Update (Health/Attack), where attributes like Health, Attack and Mana Cost are recalculated
after Auras related to them are updated
-Summon Resolution Step
-Aura Update (Health/Attack) (again)
-Death Creation Step (where mortally wounded and pending destroy minions are moved to the graveyard
and Death Events created for them)
-Aura Update (Other) (updates auras that don't use intermediate enchantments, such as Auchenai Soulpriest and Baron Rivendare)

E.g. after each outermost Phase, attributes like Health, Attack and Mana Cost recalculate twice.

We saw that Malorne had 81 attack when force played. Since his base attack is 9,
and Seal of Champions adds 3 attack every update, this means that there were exactly 24 updates 
between Seal of Champions resolving and Malorne being force-played by Deathlord.
Let's try to account for all of them.

play Seal of Champions:
...
Spell Text Phase: Seal of Champions applied to Malorne: 2 updates
(empty After Spell Phase): 2 updates

play Deathlord:
(empty On Play Phase): 2 updates
(empty Battlecry Phase): 2 updates
(empty After Play Phase): 2 updates
(empty After Summon Phase): 2 updates

play Equality:
On Play Phase: 2*Violet Teacher: 2 updates
Targeting Phase: 2 updates
Spell Text Phase: 1 Health applied: 2 updates
(empty After Spell Phase): 2 updates

play Hammer of Wrath:
On Play Phase: 2*Violet Teacher: 2 updates
Spell Text Phase: 3 damage dealt, fatigue damage taken: 2 updates
Death Phase: Deathlord DR pulls Malorne from the deck with 81 attack
Attack updates to 9

This gives us exactly 24! This is stunningly accurate.

It also tells us some interesting things:
1) We know that when we play an Overload card with Tunnel Troggs and Overload Elementals
under our control, we see an Aura Update (Health/Attack) run after the Overload Elementals
but before the Tunnel Troggs inside of the On Play Phase. It seems as though this extra update
only runs if you play a card with overload (or some related condition), because if
it ran every On Play Phase, we would get 27 updates instead of 24.
http://hearthstone.gamepedia.com/Advanced_rulebook#When_does_Overload_occur.3F

2) We know that when we play a Battlecry minion with Brann Bronzebeard in play, there is an
Aura Update (Health/Attack) between the two Battlecries. This update must therefore
only run when applicable, else we would get 25 updates instead of 24.
http://hearthstone.gamepedia.com/Advanced_rulebook#Playing.2Fsummoning_a_minion

3) There is a phenomena where sometimes, positional aura minions and their neighbours moving
will run an extra Aura Update (Health/Attack) Step at an unusual timing. We now know that
they must only run when the game wants to run one, else we'd have seen more than 24 updates.
http://hearthstone.gamepedia.com/User_talk:Patashu#confusing_aura_thing

That said, this test tells us nothing about extra Aura Update (Health/Attack) Steps that run
related to combat, ending your turn and ending the game. To explore more about those, we would
have to run the test again and take different actions, and see what attack value Malorne has
when force played.