The Bulwark beast has a thick armour which you need to break through before you are able to damage the beast. Use a pickaxe to break through the armour. The better pickaxe you have, the faster you'll break the armour. Once the armour is gone, kill it with a normal weapon(runescape money). Alternatively, use magic against it. Magic will hit through the armour, so you will not have to break it first.
 
29 Unholy cursebearer

Uses both magic and melee based attacks in Runescape. Slowly lowers all your combat stats except prayer. You can recharge your stats at the unholy fonts on either sides of the ladder, but this will restore about 1/8th of the cursebearer's life points.
 
35 Rammernaut

Rammernaut only uses melee, but will use a strong attack to disable the protect from melee prayer if you try to use it, so you need to fight it without the prayer. Rammernaut has a ram attack, which can deal high damage. Before doing this attack in game(Runescape powerleveling). If you stand next to a wall before he charges, you can dodge his attack by moving away from the wall, resulting in Rammernaut ramming the wall. Since he only does melee damage, good melee armour is highly advised. Rammernaut is extremely weak to magic attacks and should always be the style of combat used against him.