Purple Matrix

That'll buff right out.

The Purple Matrix (パープルマトリクス Pāpuru Matorikusu) is the vessel of the Purple Star Power, one of the Seven Lights of creation of the Precursor World. It is (questionably) entrusted to the leader of the Purple Order of the Primus Vanguard.

Fiction

Precursor World

In the final battle between the Primus Vanguard and their ancient enemy the Specters, the Purple Order leader Purple Wicked Convoy unleashed its Star Power along with the other six Lights to annihilate the Specters, which had the secondary effect of combining their multiverse into a single multicolored world.

Later, Primus, driven to omnicide by grim visions of an apocalyptic future, demanded the Purple Matrix so that he might destroy the universe, Wicked declined and returned to the Purple Planet with his Matrix. Finale Prelude

When Ultra Megatron Omega and the Blue Order's Straxuses arrived on the Purple Planet with the intention of wiping out the Purple Order, Wicked proposed that they instead join forces and use the combined Star Power of the Purple, Blue, and Silver Matrices to conquer the universe. God Neptune comic 1

Well guarded by Wicked, the Purple Matrix rested safe and sound in the matrix chamber in his chest right up until Primus, super-charged by the other six Star Powers, speared them both with one strike of the Neptune Sword, killing Wicked instantly and draining the Matrix of its Purple Star Power. Finale Prelude

Toys

Matrix Collection

If you were looking to go completionist on these, good luck.

• Mito no Machi no Matrix (November, 2012)

Mito's Town Matrix was repurposed as the Purple Matrix.

November 2012 saw the launch of the "Matrix Collection" as part of the Cybertron Satellite promotion: a set of fourteen redecos of the Matrix of Leadership accessory included with Masterpiece MP-10 Convoy, intended to be the Matrices carried by the Town Commanders, and decorated in two-tone color schemes that correspond to their bearers.

Only Mito's Town Matrix and Fukutsu's Town Matrix were released; equipped with a removable key-chain, they were available in all fourteen Cybertron Satellite stores, sold with a sticker of that region's Town Commander. They were only available with purchases of 3000 yen or more, and were limited to only 200 pieces per store.