At 1 Detachment Point this leaves 2 DP spare at Strike Force, and it needs them, because one enormous gun is not an army. Bastions of Tyranny carries no Unique Tag, so every pairing below is unambiguously legal and none is affected by the faction's unresolved tag question.
Plus [Traitoris Lance](/40k/armies/chaos-knights/detachments/traitoris-lance) (2 DP, total 3). The cleanest cause-and-effect pair in the faction. Annihilate the Unworthy needs battle-shocked targets; Traitoris Lance grants one additional chosen Dread ability at the start of the first battle round, and several Dread abilities either worsen Leadership or force Battle-shock tests. One detachment manufactures the condition the other is paid for.
Plus [Iconoclast Fiefdom](/40k/armies/chaos-knights/detachments/iconoclast-fiefdom) (1 DP, total 2). Bodies. Five hundred points of DAMNED units means something other than the Knight Tyrant is standing on objectives.
Plus [Helhunt Lance](/40k/armies/chaos-knights/detachments/helhunt-lance) (2 DP, total 3). The Knight Tyrant is a Titanic Chaos Knights model, so it sits inside Helhunt Lance's rule while Bastions of Tyranny sharpens it specifically.