Mono-Green Eldrazi leans on activated abilities from Basking Broodscale (its adapt ability) and on Eldrazi Spawn tokens (their sacrifice-for-mana ability), so Cursed Totem shuts those down and slows their mana engines. It does nothing against triggered abilities, so cast triggers and Devourer of Destiny's opening-hand and upkeep effects still work. Galvanic Blast is efficient removal for Basking Broodscale and Eldrazi Spawn tokens, and hits for 4 with Metalcraft against bigger threats like Thought-Knot Seer. Consign to Memory comes in because most of their threats and key spells are colorless, including Emrakul, the Promised End, Sowing Mycospawn, Basking Broodscale and Kozilek's Command. It can also counter their cast triggers, such as Emrakul's, Sowing Mycospawn's land search and Devourer of Destiny's exile. It can't counter Dismember, which is not colorless. Claws of Gix and Emry come out since this matchup is a race against big colorless threats rather than an artifact synergy or lifegain game. Pithing Needle is cut since the opponent's key threats (Emrakul, the Promised End; Sowing Mycospawn) are one-shot cast triggers rather than repeatable activated abilities, making it a weaker inclusion than the proactive hate and removal coming in.