Putting an end to the Bear Monster

(From MC Perspective)

Brown Armoured Earth Bear- Initial Class 2 Monster.

When my fist landed at its chest armour.

"Boom" a deafening sound reverberated in the area.

The Bear Monster's defense is almost perfect. My causal fist attack has no effect on the monster. It didn't even flinch.

I move backwards to make some distance to fight again.

The Bear Monster is completely dumbstruck, the monster surprised that its attack didn't even touch me, instead I'm the one who made a successful blow to the monster.

"Roar"

The Bear monster roared looking at above, there is nothing but dome structure ceiling there.

Next second, 

The monster turned towards me, its eyes looked fierce. I can see it's completely pissed off. Various ideas come to mind, I need to find a weak spot to attack it as quickly as possible.

Again, I used the leg technique to evade its attacks.