Yu stay to his course toward the wall, and with an arcane word he leap into the air. Up, up you go, like a giant grasshopper, over the top. He have made it, but now Yu are falling down, into the castle courtyard! He hit the ground hard, but he manage to roll with it. Fortunately, the neglected courtyard grass is nearly as tall as him and acts as a cushion.
There's a ladder nearby that he can climb to get up to the battlements.
There are four goblins at the base of the wall, chattering angrily. One of them begins climbing up the rotten rock. Yu decide this is a good place to take a stand.
There is a lot of loose rock at the top of the wall. Yu are not particularly strong, thanks to his inactive life as a wizard.
However, he expect that he could push a few Iarge rocks down upon this climber. On the other hand, he are all out in the open, and his spells would certainly be effective now.