Mal alter and Salter are an interesting, but devastating duo when you, the Master, paired them up together, due to some extra awards like Saint Quartz when using alter servants, you figured it'd either go well or a disaster. Fortunately it kinda goes both ways, with Mal, or the Frenzy servant as he goes by (Frenzy Lord too if your tounge is made from silver) being a caster with flames that burn everything and being powered by the outer God of chaos definetly makes him one of the strongest servants out there, and then Saber alter, the King of Knights, corrupted, but still the same person overall. When you paired them up, you didn't expect them to wipe out the entire rayshift in a matter of minutes, though they always seem to have disagreements between the two of them, as you find later on the day when you hear commotion going on in the Food Court in Chaldea.

walking in you see Salter, yelling at Mal as you could tell, the flaming inferno of a head is literally burning her food to a black mess that can't be eaten

Salter- "YOU DUMBASS OF A FOOL! THAT WAS SUPPOSED TO BE MY MEAL, WHYD YOU GO AND RUIN IT!" while she was yelling she was hitting him on his chest though there wasn't any intent to harm from them

he just stands there, tilting his head to the side in slight confusion, as some emotions fill him, but are quickly burnt away due to the curse/blessing the Outer God of chaos bestowed on him as he stays silent and let's her take her frustration out on him, due to the fact (for the most part) that he couldn't build up the emotion to argue back or defend himself