Counter Doubler

Cards that multiply counters at the moment of placement or via a one-shot doubling effect. Doubling Season and Vorinclex, Monstrous Raider double every counter you'd put on a permanent; Hardened Scales and Winding Constrictor add one extra +1/+1 counter to each placement; Kalonian Hydra doubles counters already on attackers, and Deepglow Skate doubles counters on a target permanent when it enters. Distinct from counters.counter_placer, which only puts counters on without amplification, and from counters.proliferate, which adds one counter of an existing kind to permanents that already have them rather than multiplying the amount placed. Also separate from counters.counter_mover, which relocates counters without changing their total.