Any spell that cause direct damage will slow down spell casting in Rappelz. If it hit hard enough or by some RNG luck, it will also cause the spell to drop. Divine Flash-disables players and monsters from using normal attack, it does not prevent them from using skills, which is why the skill is a BIG FAIL when used against another player.

The Blind Effect from "Divine Flash" disables you from using normal basic attacks e.g. meleeing -but also stops you from using attack skills and spells, because the blind effect is only suppose to stop you from meleeing. Its the debuff "Silence" that only can disable you from using attack skills and spells but you can still use normal basic attacks e.g meleeing. By the way you can buy rappelz rupees on our site when you need.

Literally in this Resurrection patch they made the debuff coding section Seal drains mana, Blind does Blind AND Silence effects combined into one blind effect.'dropping spell' happens when you take too much damage. Example, when you use return scroll, it can get canceled (or not) when a mob hits you. Same randomness as falling injuries and taming a pet. Surely you can buy Rappelz powerleveling from our site when you dont have time for your character.