I wonder, if enemy hit me with power that couse a 20dmg and make me dazed (save end) and I use Shielding Shadows or another power that reduces damage, reducing it to 0 (zero), the condition is still appied? Will I still be dazed?
Resist: Resistance means you take less damage from a specific damage type. If you have Resist 5 Fire, then anytime you take Fire damage, you reduce that damage by 5. (PHB276)
Immune: The monster has immunity to the stated kind of damage or effect. For example, a monster with "Immune Poison" never takes Poison damage and can't suffer any other ill effects from a Poison attack. (MM282)
While the Resist section doesn't specifically point out that it doesn't stop effects, the lack of mention should be sufficient. Expecially since the Immune section does speciifically mention effects.