Okay, so here's a basic plan doing the above. It's intentionally limiting the things we use to avoid him knowing all our tricks as well.
[X] Plan Speed And Counters
-[X] Remove our armor and pull out a shield.
-[X] Before the fight, reassign +4 damage damage bonus on Ignition to +8 extra dice (leaving +9 dice, +2 damage), during the fight all Firebomb Strikes will be used to propel the weapon, making sure not to heat up the weapon in a way that would cauterize anything.
-[X] Assign our 8 shapeshifting slots to Supported Grip, Increased Lung Capacity x1, Dense Muscles x2, and Adrenaline Rush x4 this turn.
-[X] Use Sundersight to analyze our opponents weaknesses as we fight
-[X] Invest 4 Orthstirr in Hugr, 2 in Fylgja, 2 in Composure, 4 in Tactics, 4 in Scouting (-16 Orthstirr)
-[X] 111d6 Attack (111d6 tricks)
-[X] 30d6 Defense (30d6 tricks)
-[X] 0d6 Intercept
-[X] Put 3 Orthstirr into 6 layers of Reinforce Shield (actually on our shield for once) before the combat begins (-3 Orthstirr) and add an instance of Explosive Reactive Armor (-9 Orthstirr, +4 Stoked Dice, 5 damage)
-[X] Activate Stoker State 4 (-12 Orthstirr), Slipstream (-8 Orthstirr),and Ember-Wing Cloak (No cost, +4 Stoked Dice) as combat begins. All subsequent actions receive +2d6 from Sunshine and Skyfire.
-[X] Put up a 120d6+7 (w/Hugareida) Atgeir Bodyguard adding 1 Odr (-126 Orthstirr, -1 Odr), and an Atgeir Counter Stab adding 1 Odr set up to do up to eleven 10d6+7 Sharpenedx4 Firebomb Strikes (-52 Orthstirr, -1 Odr, 7-9 damage each), along with two 30d6+7 Sword Guards (-34 Orthstirr each).
-[X] If we are hit in any way past our shield use Slowing Slog (-81 Orthstirr)
-[X] Stop whatever attack sequence we are making as soon as first blood is drawn
-[X] Start by using Threadcutter for nine 11d6+7 Sharpenedx4 Lightning-Charged Basic Attacks (-55 Orthstirr, -9 Stoked Dice, then +18 Stoked Dice total, 7 damage each) followed by a Sharpenedx81 Lightning-Charged Stoking Strike w/Puncture for 235d6+7 adding 15 Stoked Dice including the 9 from Threadcutter itself (-94 Orthstirr, -6 Stoked Dice, 12 damage). Follow that up with ten 20d6+7 Sharpenedx4 Lightning-Charged Firebomb-Strikes (-5 Orthstirr and +4 Stoked Dice each, 10-12 damage each).
-[X] If he puts up any Guards or visible buffs, including before the Threadcutter, use up to two 20d6+7 Devouring Blaze attacks (-8 Orthstirr, -3 Stoked Dice each, 1-2 damage each) to remove them before continuing on with the rest of our attack routine. If we seem about to go over our Dice Cap on Stoked Pool also use one then as a safety valve burning more Stoked Dice if needed to ensure that doesn't happen (though no more than, like, 21 at most, and that only if we're already over 60).
-[X] Against the first melee Trick attack against us interpose our shield, which should break Reinforce Shield and activating Explosive-Reactive Armor against the person attacking.
-[X] After that first attack use Atgeir Bodyguard to defend against all attacks first.
-[X] Against basic melee attacks or melee Trick Attacks after the first (or simultaneous with it) that get through or past Atgeir Bodyguard, default to using Contested Movement with all remaining Stoked Pool (-1 Orthstirr, 20d6+7 Hamr Roll, lose all Stoked Pool then +4 Stoked Dice) and counterattack with Sharpened Lightning Charged Firebomb Strikes w/Puncture (-11 Orthstirr, +4 Stoked Dice, 10-12 damage)
-[X] In response to ranged attacks that get through Atgeir Bodyguard or if things get by that and Contested Movement is not working or available for some reason, use as many quick-drawn Shield Sacrifices (-3 Endurance on one Shield) as needed and/or up to two 122d6+7 Fortified and Reinforcedx107 Sway defenses (-110 Orthstirr each) as seems appropriate.
-[X] If we are without a shield at any point and would otherwise use a shield or Sway instead use a 136d6+7 Orthstirr Enhanced x119 Inertia-Arresting Throw with 1 Odr added (-125 Orthstirr, -1 Odr) to both defend against and trap our opponent's sword in place.
-[X] If, and only if, we are targeted with more than three simultaneous attacks use our Sword Guards to defend against attacks 4 and 5.
-[X] If he uses any Contested Movement/Momentum-Reversal style counterattacks that force a specific stat roll, we will respond to them with Contested Movement by default, if he uses one in response to Contested Movement we will use one use of Fight of Your Life on it (+7d6), and if Hamr is included Adrenaline Rush should still apply as well.
-[X] Tactics – The idea here is to charge in with Threadcutter and hopefully hit him with something there, especially with the final Stoking Strike, and then, if that doesn't work just whittle him down (or, more likely, run his resources down) with fairly basic attacks. The key thing is that, if he attempts to attack us back, we either interpose our shield and set off an explosion at him, or counterattack with Atgeir Counter Stab and/or Contested Movement (we should get an Atgeir Counter Stab on each of his first 11 attacks, and a Contested Movement on any after the first that don't get stopped by Atgeir Bodyguard).
EDIT: Added Atgeir Bodyguard and Counter Stab.
EDIt2: Added two Sword Guards as a contingency, that's expensive given the low odds of them being needed, but I do agree that efficiency is not our primary concern here.
EDIT3: Added an Inertia-Arresting Throw if we're ever without a shield (replacing an existing rolled defense). Fiddled with a few numbers slightly.
EDIT4: Added a contingency for 'opposed roll' style counterattacks like Momentum Reversal.
