(this should be in the pathing forum, but I'll add on)
Yeah, giants in Kael remind me a lot of the yetis in the caves in Dreadlands. If you back off just a bit, they run around for a long time before figuring out how to get to you.
Also, when giants run away up the ramps around arena, they'll run into walls and glitch/warp away somewhere else (I assume in arena or around there).
Hard to explain so here's a quick MS Paint:
[You must be logged in to view images. Log in or Register.]
Green X is where you're fighting a giant. Red line is where it starts to run. Blue circle is when it hits the wall and warps somewhere, bringing a huge train.