Tonight, they would pay.
After the events of last night, Saber had resolved to find the dragon that was responsible for the destruction of his Master's home. He did not care about whatever personal history that was shared between the Lancer who had found his way to his midst and the Berserker who wished him dead. He did not even care about the Berserker's hidden identity, or whatever connection he had to its anger. All that was on Saber's mind was the extermination of this dragon, both for the potential liability it would be and, more importantly, the audacity it had to attack Saber in his own home. The rage that welled up within Saber was already near its peak, and he had hoped that his Master's plan of bringing them out would lead to their long-awaited confrontation.
However, the fleeting signs of their presence slowly fading only made Saber angrier.
The Servant rushed into the building, smashing its way down the basement with little effort. It did not take him long to find (and smash through) the golem blocking the pair's escape route. While he briefly considered following them in, he did not want to risk a fight underground that would likely result in all of Paris crumbling down on top of the both of them. Despite having the advantage of initiating combat in such an enclosed space, having been trapped in a pit of dragons in his youth and successfully fighting them off with his bare hands, Saber instead decided to start the battle on his own terms.
If they wished to flee through the sealed, claustrophobic tunnels of subterranean Paris, then Saber would just flush them out.
The fires of hatred for this Berserker grew within Saber's very being as he began to exhale, his helmet opening up fully to allow him to release his flames. Hellfire spewed forth from Saber's mouth as it began to fill the tunnels with his manifested rage. Hot enough to evaporate whatever stagnant water flows through these dark crevices, the accursed flames made their way through the tunnels as they sought out the same "exit" that Madhisi would wish to find, seeking oxygen and burning everything in its path. In regards to Mordred, the demonic flames seethed with greater intensity as they seek to burn through her protective scales. The question of if Mordred was able to survive being engulfed with the cursed flames created to end existences such as her would be moot if she were unable to protect her Master from such biting flames.
Despite this, Saber proceeded onward, Nagelring in one hand, and something far more hideous in the other...