Hey guys its been a long time since i've played because uni work got the better of me. I've started a new party multi-class fighter/mage, riskbreaker, beserker, necro, priest of lathander, and cernd(auramaster). The party i've got is pretty high level with both fighters and necro at level 13(verging on 14), and i've taken care of most of the quests in chapter 2-3 but i cant complete the fighters stronghold because i cant kill lord reonall and his army, lord reonall is practically invincible, his physical resistance to all forms of damage is extremelly high(i can only get at max 5 damage with any weapon type i'm weilding) and when he has hardiness hes physically immune, he's apparently immune to all spells 5th level and lower so breach doesn't work, has got alot of hitpoints and high regeneration. Most of his army can be disabled through enchantment spells but even they are tough with each of reonalls guards each of them able to use hardiness(though are vulnerable to magic at least), golems and a high level mage to boot.
Really this battle is crazier than the shade lord battle, need some advice or do i need a higher level party to beat him.

Dude, they are sooo ahead of you.

If you are new to the mod, just like I am (IA v.5 is my first try of this incredible mod) the most reasonable level for that sturdy bunch of heavy! damage dealers is IMO around 20 (or higher!).

The battle with Lord Roenall triggers many weeks after gaining the stronghold. I wonder what you were doing during this long period of time. You could go to underdark and return and do many other quests. The party levels are normally far higher than 13 or 14 when this battle triggers.

well i past the weeks away by resting because i wanted to complete the fighters stronghold before i went to spellhold. I thought that reonall was just gonna be another one of those high level fighters, but i guess i was quite wrong in that regards.

Question - is Roenall immune to all 5th and lower lvl spells? What is he, a Lich on steroids ? I fought this battle only twice , I noticed he is immune to "Breach", but didn't bother with using magic against him. But I've also noticed there are other powerful fighter-type characters immune to "Breach" but not immune to, say, "magic missile" etc.

You're right that there are characters who are immune to Breach but not 5th level and lower spells (also there are characters who are immune to the Lower Resistance spell without being immune to any spell levels). I believe this is true for Roenall.

Oh so reonall's hardiness can be dispelled via higher level spells or a high level remove magic right? Or would it be best to lower resistance and use magic to kill him

No, I'm afraid not, since Breach is the only spell that removes Hardiness.

I wonder, what is the Wis of your F/M? If it is 14+ then you could read the scroll of Limited Wish bought from the scroll merchant in the back of the Adventurer's Mart and use the one-time wish for control over time (=Timestop). Provided you haven't already bought the scroll and written it into someone's spellbook... Perhaps you could kill Roenall by timing the use of the scroll so that Roenall has not yet used Hardiness, and kill him outright with your F/M while time is stopped? He won't regenerate during TS, nor will he activate Hardiness.

I wonder if this batte is the best place to use a one-time limited wish..
Why don't you leave the battle until you're stronger, after Spellhold and Bodhi and returning the Lanthorn to Suldanesselar? Even 1 or two HLAs for your fighters will do a big difference in this battle. I agree that using limited wish is certainly the easiest way to kill him at your levels. I wouldn't use it here, the battle is not that hard on higher levels.