UW Control aims to answer your threats one-for-one with counterspells and removal while building to a late-game win through card advantage engines. Meltstrider's Resolve is your most important sideboard card here, protecting your key permanents from wraths and targeted interaction. Mossborn Hydra and Surrak provide threats that are either difficult to counter or generate immediate value even when answered. Webstrike Elite and Leatherhead come out as they are more effective in aggressive matchups where their stats matter; Archdruid's Charm is too conditional against a deck with few relevant targets to hit. Keep the pressure on early with your landfall engine and force them to spend counters on your threats before resolving a protected Hydra.