It's been a while since I contributed, so I thought I'd give it a shot.
In the incredible amount of powerlevelling reposts, it says that you should level from 8-14 in RFC. It's hard to make sure the alt survives this, but if you walljump him to this location, he'll most likely survive.
peecee.dk | Vis upload
The monsters will _NOT_ evade. They'll follow the yellow line up to where you're standing. The green line is how you should walljump up.
EnjoyThe monsters will (most likely, depending on gear) be dead before they reach you. If they reach you, you can just jump down and watch them follow the yellow line back to reach you again.
EDIT: To make sure no misunderstandings are made, I tested this, and it works.