12 life is a long road to climb, particularly considering that Jurgen won’t just give you the win if you choose to play it out. Fortunately, you have quite a lot of direct damage in hand, and Arcbond can help you here. Unfortunately, your opponent’s creatures aren’t very durable — as unintuitive as it sounds, you’ll need to keep them alive long enough to kill them.

1. Tap three forests to add (all used as generic mana) to your mana pool.
2. Spend to turn Rattleclaw Mystic face-up. Rattleclaw Mystic’s ability triggers, adding (all but used as generic mana) to your mana pool. (You now have in your mana pool.)
3. Spend to equip Heart-Piercer Bow to Destructor Dragon.
4. Spend to cast Arcbond on Unyielding Krumar.
5. Declare the start of your combat phase, assigning Destructor Dragon to attack.
6. Heart-Piercer Bow triggers. Choose to have it deal 1 damage to Longshot Squad.
7. Tap a mountain to add to your mana pool.
8. Spend to cast Wild Slash on Unyielding Krumar, dealing 2 damage to it. Because of Arcbond, Unyielding Krumar deals 2 damage to each other creature and player. Abzan Skycaptain, Longshot Squad, Highland Game, and Rattleclaw Mystic all die. Jurgen is now at 10 life. You are now at 3 life.
9. Abzan Skycaptain’s ability triggers. Since Unyielding Krumar is the only remaining creature Jurgen controls, Jurgen puts two +1/+1 counters on it. Unyielding Krumar is now a 5/5 creature (with 2 damage on it).
10. Highland Game’s ability triggers, and you gain 2 life. You are now at 5 life.
11. Destructor Dragon deals 4 damage to Jurgen. Jurgen is now at 6 life.
12. At the beginning of your second main phase, tap two islands to add (both used as generic mana), and one mountain to add to your mana pool.
13. Spend to cast Bathe in Dragonfire on Unyielding Krumar, dealing 4 damage to it. Because of Arcbond, Unyielding Krumar deals 4 damage to each other creature and player. Unyielding Krumar and Destructor Dragon both die. Jurgen is now at 2 life. You are now at 1 life.
14. Destructor Dragon’s ability triggers. Choose to destroy Jurgen’s Suspension Field.
15. When Suspension Field is destroyed, Mardu Heart-Piercer returns to the battlefield under your control.
16. Mardu Heart-Piercer’s Raid ability triggers. Choose to have it deal 2 damage to Jurgen, defeating him.