and I just started playing.  My main character is level 14, my henchmen are level 13-11 and I have 3 henchmen: spear, gunner, archer.  Im playing a sword

Im stuck on the quest to defeat the Diseased Tree.  I get completely wiped by my second turn.  I have to be doing something wrong because I was given this quest at level 10 I think.  However, according to the "odds" interface its telling me I have just over a 50% chance of defeating this encounter.

so, I have no more quests..am I suppose to grind up levels to complete this objective?  If so, does this happen often in the game?

Hmmmm, you meant the Mutant Tree? This guy?

http://www.atlantica-db.com/monster/sword/mutated-tree-250

Hmmm, I've done that 4 times and I never had any trouble. Are you using any gear?

I also think you can party up to tackle it. So try asking around?

For the next boss, Hellish Fairy, you should use scrolls. But I guess you don't have any yet.

well, I found someone else who was stuck so we grouped.  I guess I wasnt the only one.