Kelly is at a relatively low life total, but her Platinum Emperion is currently stopping any attempts to get it to zero. While the Emperion can certainly be destroyed, doing so would take a good amount of your (limited) resources and leave you unable to deal enough damage. Fortunately, there are alternate means to win without getting rid of the big metal monster.

1. Tap Salvaging Station to return Altar of the Brood from your graveyard to the battlefield under your control.
2. Play the swamp from your hand. Altar of the Brood’s ability triggers, putting the top card of Kelly’s library into her graveyard. Kelly has 35 cards remaining in her library.
3. Tap Serrated Biskelion to put a -1/-1 counter on both itself and Workhorse. Workhorse is now a 1/1 creature.
4. Tap Staff of Nin to deal 1 damage to Workhorse. Workhorse dies and is put into Kelly’s graveyard.
5. Salvaging Station’s second ability triggers, and it untaps.
6. Tap Salvaging Station to return Seat of the Synod from your graveyard to the battlefield under your control. Altar of the Brood’s ability triggers, putting the top card of Kelly’s library into her graveyard. Kelly has 34 cards remaining in her library.
7. Tap a swamp to add to your mana pool.
8. Spend to cast Reanimate on Kelly’s Workhorse, returning it to the battlefield under your control. You lose 6 life, and are now at 2 life. Workhorse enters the battlefield with four +1/+1 counters on it. Altar of the Brood’s ability triggers, putting the top card of Kelly’s library into her graveyard. Kelly has 33 cards remaining in her library.
9. Remove three +1/+1 counters from Workhorse to add to your mana pool. Workhorse is now a 1/1 creature.
10. Tap Seat of the Synod to add to your mana pool.
11. Spend to cast March of the Machines, turning all noncreature artifacts into artifact creatures with power and toughness each equal to their mana costs. Altar of the Brood’s ability triggers, putting the top card of Kelly’s library into her graveyard. Kelly has 32 cards remaining in her library.
12. Darksteel Citadel and Seat of the Synod each become 0/0 creatures, and die.
13. Salvaging Station’s second ability triggers, and it untaps. (In actuality, it triggers twice, but you only need one triggered ability.)
14. Tap Salvaging Station to return Seat of the Synod from your graveyard to the battlefield under your control. Seat of the Synod enters the battlefield as a 0/0 creature due to March of the Machines, and dies. Salvaging Station’s second ability then triggers, and it untaps. Each time Seat of the Synod enters the battlefield, Altar of the Brood’s ability triggers, putting the top card of Kelly’s library into her graveyard.
15. Repeat the above step until Kelly has no cards remaining in her library.
16. Declare the end of your turn.
17. On Kelly’s draw step, Kelly is unable to draw a card due to her empty library, allowing you to win the game.