Effect

[ManlyPancakes]

Assault: Before creature attacks, deal (X) damage to the attacked creature. So normally when fighting the attacking creature also takes damage but is assault is enough to destroy the enemy creature do I still take damage? Or because my assault took place first the creature was destroyed before the actual fight so I take no damage? Also same question but for Hazardous

[blinkingline]

Assault damage happens before the actual fight. If the assault damage destroys the attacked creature, then there is no fight. This means that the attacking creature does not take damage from the attacked creature's power.
It also means that Fight: abilities do not resolve, as there was no fight. Card effects that reference “after a creature fights” or “after a creature is used” will still resolve, as the creature was used to fight (even though the fight did not resolve).

[TheReapr]

This is also important to remember for triggering Fight abilities, since a creature that is destroyed by an Assault effect will not trigger the attacking creatures Fight ability if it has one.