X-Demon Bonus Buy Slot by Evoplay

Three buy-in tiers split the free spins entry: 30x for 8 spins, 52x for 10, or 86x for 12. That tier choice matters more here than in most buy bonus slots because the free spins round runs on a collection system - six demon types each have their own meter, and every meter you complete before the round ends converts that demon into a permanent Golden Wild. More starting spins means more Wild Attack triggers, which means more meter progress. The 86x option gives roughly 50% more chances than the 30x entry, and at these volatility levels, those extra four spins shift the math noticeably.

The Wild Attack mechanic itself is unusual. A hidden sixth row sits above the main grid, invisible to paylines, and Wild Attack symbols only appear there. When one lands directly above a demon symbol, it zaps that demon into a Wild for the spin. During free spins, each zap also ticks down that demon type's collection meter. Complete a meter and you get the permanent Golden Wild plus 2 extra spins added to the counter. Stack three or four Golden Wilds across the reels and the later spins start compounding.

Two bronze gargoyle statues guard the grid, wings spread wide, with glowing cyan braziers at their feet. The demon symbols are round, shield-shaped icons in saturated blues, greens, purples, and magentas against a deep green backdrop. The base X-Demon plays identically but forces you into the standard scatter trigger - three Bonus symbols for 8 spins, four for 10, five for 12.