Overview:

This is a Grixis combo deck that uses Mairsil, the Pretender to accumulate powerful activated abilities from exiled cards, enabling various infinite combos and value engines while maintaining strong control elements.

Primer:

The deck's primary strategy revolves around getting Mairsil, the Pretender onto the battlefield and exiling key creatures and artifacts with cage counters to grant him their abilities. The deck uses tutors, looting effects, and mill to get specific combo pieces either into exile or the graveyard. Key combinations include using Aetherling abilities for protection, Tree of Perdition for life total manipulation, and various untap effects to bypass Mairsil's "once per turn" restriction.

The deck maintains control of the game through counterspells and removal while assembling its pieces. Secondary win conditions include mill strategies with cards like Dreamborn Muse and Laboratory Maniac, or generating value through artifacts and powerful spells like Expropriate. The deck can also win through commander damage after protecting Mairsil with various abilities from exiled cards.

Weaknesses:

• Heavy reliance on the commander makes it vulnerable to repeated removal or tuck effects
• Graveyard hate severely impacts the deck's ability to execute its strategy
• Can struggle against aggressive strategies before establishing control
• Vulnerable to artifact/enchantment removal that hits key pieces

Most Important Cards:

1. Aetherling
2. Staff of Domination
3. Tree of Perdition
4. Lightning Greaves
5. Demonic Tutor
6. Entomb
7. Time Sieve
8. Laboratory Maniac
9. Phyrexian Metamorph
10. Conjurer's Closet

Attribute Ratings:

• Speed: 6/10
• Resilience: 7/10
• Consistency: 7/10
• Interaction: 8/10

Rating Justification:

This deck operates at a focused competitive level, typically threatening wins around turns 6-7 through its commander-centric combo lines. While it includes powerful interaction and tutors, it's not quite fast enough to compete with true cEDH decks. The presence of multiple backup plans and strong control elements puts it above casual builds, but the reliance on the commander and somewhat slower combo setup keeps it from reaching higher power levels.

Final power level rating: 7.0 - 7.5

The deck shows strong optimization and includes multiple paths to victory, but its commander-centric nature and the timing restrictions on Mairsil's abilities prevent it from reaching true cEDH levels. It sits comfortably in the focused competitive range, capable of threatening wins through various lines while maintaining interaction with opponents' strategies.