Gruul Basking Broodscale is a combo deck that wins by sacrificing Basking Broodscale repeatedly with Blade of the Bloodchief and Glaring Fleshraker to generate infinite mana and drain, with Urza's Saga providing artifact tutors and Walking Ballista as a backup win condition. Your critical counterspells are Counterspell and Consign to Memory — Consign handles Urza's Saga tokens, Blade of the Bloodchief, and the Walking Ballista kill, while its free-cast mode is easy to trigger given their artifact-heavy setup. Orim's Chant is excellent on their combo turn to completely freeze their action, and Force of Negation provides a free counter when you can't tap mana. Rest in Peace doesn't directly hate on the combo but does blank their Shifting Woodland recursion and Bog Juka synergies. Sweepers are mostly dead since their creatures are large Eldrazi and combo pieces rather than small aggro threats, so trim them to maximize your reactive suite.