I want a lowball drink that is kind of sweet and strong.

Given your preference for a lowball drink that is both sweet and strong, an excellent choice would be the Flat Coke cocktail. With a cocktail score of 3.67/5, this drink promises a potent mix with its 26.67% alcohol content and a total volume of 90ml. The Flat Coke cleverly blends the warm, rich notes of whiskey with the deep, roasted flavors of coffee liqueur. Despite its name, there’s no actual soda involved, which further highlights its unique naming—possibly inspired by its exquisite blend of flavors reminiscent of those in cola yet richer and more profound. This cocktail should satisfy someone looking for a balance between sweetness and strength, especially if they enjoy the sophistication that comes with coffee-infused beverages.

Another compelling option is the Whisky and Coke. While its sweetness stems from the cola, this classic cocktail enjoys immense popularity, thanks to the sophisticated balance it achieves between the intensity of whiskey and the light, vanilla-tinged sweetness of cola. Although its alcohol content at 6.86% might not be as strong as some of your other choices, it's a beloved classic still known for its robust yet pleasant flavor profile. With a high rating of 4.7/5, it’s one of those drinks that any whiskey lover would appreciate, especially when craving something on the sweeter side without overwhelming the senses.