This is a dangerous cheese lane. Darius relies on landing to force kills, while you want to poke from distance. If he catches you, you likely die, but if you space well, he becomes a useless meatbag.
Darius mid is a cheese pick that relies on catching you with and Ghost to run you down. Because the mid lane is shorter than top, you have the advantage if you maintain spacing. You win by poking him out of lane and out-scaling him in teamfights.
This is a favorable matchup for Swain because Teemo's signature blind does nothing to stop your spell damage. You significantly out-sustain him and can reveal his stealth using .
Swain generally favors this matchup because Teemo's blind does not stop Swain's spell-based damage. You provide significantly more utility and teamfight presence, and your can reveal Teemo if he tries to hide using .