Welcome to the Arena of Valor (AoV) Dark-Slayer-lane Tier List. Here, I will present the current Solo queue hierarchy of DS-lane champions.
Jungle Mid Marksman Support
Top lane is currently dominated by two assassins, Florentino and Riktor. Florentino seems like in dire need of nerfing or for the community to find new ways of dealing with this flower-gatherer. Maloch and Marja are safe and good options if we need a tank(ish) hero.
DS lane meta is in the state of constant flux, constantly rotating between high damage/assassin, and more durable warrior/tank type of champions. DS-lane and Support role are two roles providing toughness/resilience. So bear in mind, if your ally has picked squishy support, then get the tank for DS lane, and vice-versa. It is not a problem if both pick tank(y) characters, but having none can be a huge and potentially unsolvable problem. DS laners need to have a strong presence, they cannot afford to be bullied, because falling back to tower incur 10% gold penalty and higher difficulty of last hitting minions. Maloch is probably still the most complete DS laner around.