Silver Tower of Tzeentch
The Silver Tower of Tzeentch AKA the flying Super Mario Level is a Daemon Engine of Tzeentch, the Dark God of Sorcery. A Silver Tower as you can imagine from its nickname is ridiculous. The only reason why it avoids the stamp of Fail unlike half of Khorne's Daemon Engines is because it comes from Tzeentch who is known to not give a flying fuck on making sense, so it can afford in looking as bizarre as possible. The flying Mario Level is a collection of stunningly beautiful, intricately carved towers resting upon a circular disc; it floats above the battlefield supported by nothing but sorcery. Each Silver Tower is subtly different in its creation, yet all are disturbingly beautiful, with fine snouts of weird, magically-powered weapons studding forth from their walls. Each tower is of full of dozens of Tzeentchian Thrall Wizards, who all focus their powers to rain magical destruction upon the foes of their master below. The Thrall-wizards do not control the tower itself, as it is controlled by a trapped daemon of Tzeentch, this meaning that if the thralls are all slain, then the tower can simply retreat to gather more.
In addition to its considerable offensive capability, a Silver Tower is protected by powerful wards which form a wall of energy shielding not only the Tower itself, but also other nearby allied vehicles and infantry.
Seriously we aren't kidding that the flying castle looks completely out of place for WH40K. Damn it Tzeentch!
Weaponry
The Silver Tower's weapon systems are powered by the Thrall-wizards that operate within the tower. These psykers power the tower's many weapons using the power of the Warp, and thus all weapons used by the tower fire beams of pure Warp energy at their targets. Each Silver Tower is usually armed with at least a single turret-mounted Beam of Power weapon which serves as the tower's primary offensive weapon. It is powerful enough to engage and destroy enemy armoured vehicles. The tower is also armed with several other turret-mounted weapons known as Bolts of Change. These weapons are not as powerful as the Beam of Power weapon, but instead feature a higher rate of fire than the tower's main weapon. The Bolt of Change are fired in volleys, and the number of shots fired from the tower's secondary weapons are always random, as befitting the Lord of Change.
The exact number of secondary cannons mounted on the construct are unknown to the Inquisition, though the number may simply be different from one Silver Tower to the next, as befitting the randomness and love of change for its own sake of Tzeentch.