I am trying to complete a quest,but i don't have much power.i keep killing my pets,what can i do?

I suggest you work on missions with your pets and level them up a bit first. I would also suggest that your armor matches your chosen statistics tree, so points don't get waisted.

Pined Scathreoite Because he's better at explaining this stuff then me.

Thanks!I will try to do that.thanks again

Draumrkopa, well, I can't say I'm really much of a quest person (Quests Completed: 19 >`_>) because I find them kind of tedious for not much reward.

Might depend on what quest it is, but yes, equipment is important.
Black Pearl needs a different relic, because he's attuned to earth, a physical/strength element, but his relic is an evoker relic, which is magical/intelligence, so he's not getting a boost from it (even if the other equipment doesn't match with the element, you definitely want your relic to match because it's the thing that gives the major attack boost.)
You should also look to finding a strength oriented armor. The levels of his equips are fine, just look to upgrading the rarity when you can (Rarity > level- for instance, we go for legendary level 50 equips over epic level 60 because legendary equips just have better stats than epics.)

Blue Moth only has uncommon equips, two of which are level 0, so it's her you want to look into more (though her relic is at least aligned with her element)

So, yes, go for missions for a bit. They'll help to raise your pets' exp, get you gold, healing items, and equipment that you can either use or sell.