Finally took the 3 stones from the 3 small dungeons that were necessary to unlock the stairs in the Lesimas dungeon.
It was surprisingly a piece of cake, i guess it means my character and allies are ready.
So after going to Lesimas, and beyond the locked stair and the story (elona custom re-adding it) being told every few levels, i run into a mid boss i didn't remembered the last time i went there "Alsapia the murderer mask", maybe it's an Elona+ guy (as the last time i won Lesimas it was the original Elona) but after a short dialogue the fight began and he went down very fast.
What was much more annoying is that in the large room he wasn't alone there were a lot of invisible enemies, and i had no way to see them and stupidly had left all my potions back in my storage room so i couldn't reveal them by throwing randomly potion to make them wet and so reveal them.
So my squad was taking small damage (fortunately) without retaliating.
Fortunately, it's still possible to deal with them by using the target key ( the * key) and aim at a tile, if there's none there, there's a message "you aim at the ground" , but if there's an invisible guy it's "you aim at something" .
There was a bunch of those guys but with the targetting thing i finally managed to get rid of them.
Then on a later level, i ran into an "elec Dragon" , as i was more or less one shotting everything that wasn't an unique or boosted monster, i shot, and again and again, while noticing this "elec Dragon" health was going down extremely slowly, much more slowly than any boss i took down so far.
Then he attacked and one shotted 3 of my 4 allies , letting only me and my powerhouse warrior (the little girl) , and a couple of turns later i was alone vs the elec Dragon.
Unfortunately my roguelike problem appeared :
I mean "there's no way that monster will resist my most powerfull spells, i annihilated everything until then, i sure could teleport away to the stairs at any time and escape unscathed, but that monster MUST die there's no other way"
And my character died.
I came back with my squad and ... we all died again.
Damn, can't believe this single enemy is so much more powerfull than anything my troopers destroyed so far.
Sure i could just avoid easily that elec Dragon as the stairs are not far from each other, but ... you know ... "that monster MUST die there's no other way"