Lesser Demon

I'm lvl 60 on there I kill them alot as lvl 28 mage ..... I suggest using mage is is best way to kill cause it has high attack rate

Alright, I will try and help you, but first remember that I am no longer a player of Runescape. I quit a long time ago, but my knowledge should be enough to help you. I would say that the best method to kill a Lesser demon, or any monster that is stronger than you is to level up your strongest attack level. If you use strength as your main stat, then just focus on leveling that up. If your guy is a mage pure, or uses attack only, then work on increasing that, because you will need it. I just leveled up my range, and got the newest bow by chopping down trees for gold. Then you could stand behind a door, gate, or fence and just shoot arrows at the opponent while they are still trying to reach you. A very effective method to be sure. You could do it the way I listed, or use prayers to help your attacks become stronger.

I am sorry, but it's been a while, hope I helped.

Alright as being a senior player of Runescape I will try to help you. Now first off I need to know where the location is of this lessar. If you mean in the kamajara volcano then all you have to do is hide in the rocks and either use mage or range. However if you only wish to melee him then I suggest you use very good armor and you also use a lot of food with you on the trip. I don't suggest you try to actually slay the monster with your current level, though your best bet in slaying the monster that over powers you is to range or mage him.

Use mage best for me it dmges a lot like fire blast max hit 14.
Then think f the others.
Hehehe

Just get you're magic lvl up to 33 and use earth bolt on the demon,I killed the lv 82 demon in melzar's maze with an air staff and wizard hat by using earth bolt,and also carry many lobsters with you,if you can't cook them den buy them from the grand exchange.