Canon kidou used by Urahara:
Kuyou Shibari (Nine Sunlight Traps) - Bakudou #79, 4000 Kidou
Description: Creates eight black holes that emit spiritual energy in the space surrounding the target. The combined pressure tugs the target in all directions, threatening to pull their body apart. A final black hole manifests in the center of the target's chest, tightening the hold. The first hadou cast while this spell is active will be drawn immediately and entirely to the bound target.
Incantation: Cast a memorial for heavenly light, buried in the traps of consummate darkness. Stolen shadows, rod of enmity, cast forth and draw in. Bakudou #79, Kuyou Shibari.
Senju Kouten Taihou (Thousand Hand Bright Heavenly Flare) - Hadou #91, 6800 Kidou
Description: Summons numerous spears of light that appear in the air surrounding the user. As the spell is completed, the dozens of spears are all fired directly forward at once, bursting outward in a spread formation. On impact, each spear detonates in a 5-yard radius explosion of searing light.
Incantation: Limit of the thousands hands, sacred hands of unreachable darkness, shooting hands of the invisible sky. The path that drops light, wind that stirs up the embers; do not hesitate to gather, look at my fingers. Light bullets, eight bodies, nine articles, tome of heaven, diseased treasure, great wheel, grey turret. Aim far away and disappear brightly. Hadou #91, Senju Kouten Taihou!
I'm not sure if this is how they worked in canon, but I thought it would explain the use of the black hole bakudou. So, rather than generic bind + generic auto-hit attack, we have light spear shotgun and a high-level binding with a more powerful Curse Mark.
Kuyou Shibari (Nine Sunlight Traps) - Bakudou #79, 4000 Kidou
Description: Creates eight black holes that emit spiritual energy in the space surrounding the target. The combined pressure tugs the target in all directions, threatening to pull their body apart. A final black hole manifests in the center of the target's chest, tightening the hold. The first hadou cast while this spell is active will be drawn immediately and entirely to the bound target.
Incantation: Cast a memorial for heavenly light, buried in the traps of consummate darkness. Stolen shadows, rod of enmity, cast forth and draw in. Bakudou #79, Kuyou Shibari.
Senju Kouten Taihou (Thousand Hand Bright Heavenly Flare) - Hadou #91, 6800 Kidou
Description: Summons numerous spears of light that appear in the air surrounding the user. As the spell is completed, the dozens of spears are all fired directly forward at once, bursting outward in a spread formation. On impact, each spear detonates in a 5-yard radius explosion of searing light.
Incantation: Limit of the thousands hands, sacred hands of unreachable darkness, shooting hands of the invisible sky. The path that drops light, wind that stirs up the embers; do not hesitate to gather, look at my fingers. Light bullets, eight bodies, nine articles, tome of heaven, diseased treasure, great wheel, grey turret. Aim far away and disappear brightly. Hadou #91, Senju Kouten Taihou!
I'm not sure if this is how they worked in canon, but I thought it would explain the use of the black hole bakudou. So, rather than generic bind + generic auto-hit attack, we have light spear shotgun and a high-level binding with a more powerful Curse Mark.