A general overview of the bosses in RD and strategies to defeat them.
Boss 1: Difficulty 1/5
Quite an easy fight. Position your group behind the chest high wall in front of the platform that Rictus stands on. The reason for this is that Rictus AOE pulls every now and then and the wall prevents everyone getting yoinked and face melted. Unless you're Mijjah and love to get pulled in just for lols :P
I think he also has a small knock-back so I usually tank him at the bottom of the stairs against a pillar so that everyone has LoS and I don't get punted around.
Easy fight tank and spank.
Boss 2: Difficulty 2/5
Wormwood or Treebeard as I call him.
Another simple tank and spank. Pull Treebeard and tank him in the middle of the big pond. Beware he has a knock-back so don't go getting kicked into trees and LoS-ing your healer.
He will also summon funky looking magic mushrooms at player's feet. Move away from them, if you don't they basically explode and do a lot of AOE damage. Towards the end of the fight Treebeard will summon quite a few around so just be wary of group wide damage and try to keep focused on your positioning.
Boss 3: Difficulty 2/5
Quite an easy fight. Basically you tank him towards the center of the tanking area. Try to put your back facing one of the pillars as he does a knock-back every now and then. Its not that large so it may not be an issue. I usually just take it.
Now here is the issue, hopefully your DPS don't get tunnel vision and focus on their rotations because Falidor will cast Glacial Shield on himself. Hitting the fella while its active will do quite a bit of damage back. Stop DPS, wait for the stacks to fall off and continue DPS.
Just don't kill yourself with it because your group will laugh at you :D
Please note that this summary of bosses is for Normal mode Runic Descent only and may contain misinformation or mistakes.