The plasma discs of Plasma AA Batteries, Seekers and Photon Cannon can be switched to far more dangerous Tiberium shards
Following excessive Tiberium infusion, some Scrin units mutated and "evolved". Most plasma-disc launching units (in particular, Seekers, Plasma Missile Batteries, and Photon Cannons) were adjusted to be able to project Tiberium shards instead of their standard weapons, increasing their attack power. Any Scrin faction could access this upgrade at a Technology Assembler. The upgrade costs $2500 and requires 1:15 to complete.
Some other Scrin units, such as the anti-infantry Ravagers and the Mechapede are also employ Tiberium shard weaponry. The Reaper-17 Scrin sub-faction has Shard Walkers instead of Gun Walkers. Additionally, they can upgrade the green shards employed by Shard Walkers and Ravagers further, changing them into Blue Shards, which are more powerful than their green variants.
It's also worth noting that Tiberium Fiends also use Tiberium shards as a weapon.