iirc there are bonuses given to your main if its an explorer
i remember cygnus knight providing some sort of bonus to the highest level explorer or something
What other bonuses are there and how do they work?

I believe, right now, that the Angelic Buster gives you this Exp jar.

If you make it to 30 on your AB, it gives you a jar that allows you to instantly level another character to 30.

Also give you another jar at 70, that allows you to instantly level a character from 30-70.

Luminous gives flat Int. and is super easy to level.

You'll want to Google maplestory character card system and maplestory link skills. Too much info to post here

I think he meant like the attack bonus for having a character lvl 200 and a cygnus lvl 120

Your highest level CK gives bonus to all your characters.
Your highest level character gives bonus to all the rest of your characters.
The second highest level character gives bonus to your highest level character.

Bonus = Blessing thing (attack, magic attack), I forgot exact name.

Hope I made sense.

Yea this is what I was talking about, thanks. I was wondering if they added or changed anything as of late, I haven't played in awhile.