Can someone help explain aggro

Greetings to all, I'm new at this game and to mmos in general. I only ended up playing because I was looking for games in Google play lol. I very much enjoy Toram so far but I'm confused with this aggro business.
My problem is I worked out how to hire mercs and such but even though my attack is weak and merc is strong, as soon as I do ANYTHING the boss makes a beeline straight for my candy. My attack does like 300 my merc does 1500, why does boss bother with me so much? Even when I played with my brother who is a much higher level (I'm lvl 30 he is level 70) boss just can't get enough of me. He said to ask you guys lol sorry for the nub question and thanks in advance

 

Mercenary, specifically an attacker type, has the atk doubled from the actual player Stat. So if you have 300 atk and then register your character as mercenary the mercenary will have 600 atk that's why mercenary auto attacks are considerably more powerful relative to the attack Stat.

Here is the thread regarding mercenary:
https://toramonline.com/index.php?threads/everything-you-need-to-know-about-mercenaries.33957/

As for the aggro, there is aggro point, which generated from the use of skills, initiating attack and auto attack. Initiating battle generates 200 ap, each auto attack generates 10 ap. Aggro point from skills is equal to the original mp cost of each skills.
Skills also generates aggro differently, whether it's upon hit, whole area aggro(party aggro), or self aggro(aggro generated to your targets only).
Here is a video regarding the basic of aggro:

 

Thank you for your help I appreciate it, I'll watch the video!
I chose mage if that makes any difference. Is there a way I can make merc initiate attack or is that something I just have to deal with? I suppose they can't really make it too easy for us))

 

Mercenary can't do anything other than doing auto attacks, or reviving you when you're dead. They can't initiate battle.

But, a defender type mercenary generates 100 aggro points for each successful attacks. So taking over the initiation aggro is pretty simple. Still, unless you have - 100%aggro on your gears. Using mercenary as a tank is not really practical. As skills generates way more ap than mercenary's aggro output

 

Not on a -100% aggro class which I currently use atm. I can solo some boses with the help of my tank merc and spam all I want with my bg md sub.

Mage seriously need -aggro gears ffs.

 

Copy that. Thank you again for your time and help.
Im not struggle too much so far just not sure what things do what)

 

switching aggro (when the red arrow moves to another player) also adds 200 points to the receiver's count.
so if you have the most aggro and the boss targets you, you will get additional 200 aggro score. a defender merc will need to hit the boss at least 3 times to take back the bosses attention.

-x% aggro stats reduce the aggro generated by your attacks by a fraction, but actions such as initiating battle or switching aggro always generate 200 points regardless.
certain skills will also add a fixed amount in addition to the usual amount.

another factor is the target range.
single-target attacks will generate aggro on the target only. AoE attacks generate aggro on every monster they hit.
self-buff skills generate aggro on the monster you are currently targeting.
party-buff skills will generate aggro on every monster on the field.

 

Exactly the information I was looking for. Good man thank you!