Basking Broodscale sees play as part of a combo deck that goes infinite with the Eldrazi and Blade of the Bloodchief, forming a simple loop that often wins with Glaring Fleshraker or Walking Ballista
In this case, hes become a dashing knight complete with armor and a two-handed claymore so big it would make Cloud Strife jealous which certainly accounts for his immense power level
Simic Sky Swallower / Sagu Mauler You can't win the game without dropping someone's life down to 0, unless you have a funky win-con or milling thing going on, but not generally
You are going to tap your Sergeant for a two-mana fetcher, and then tap that fetcher, for a three-mana fetcher, and so forth, until you win with 5-6 Rebels out
If Dark Depths leaves the battlefield before its triggered ability resolves, you won't be able to sacrifice it, so you won't create Marit Lage