Trading???

there's already a way to level up gifted monster easily. Imagine a level 50 monster who has only about 1000 exp left to level up. Gift the monster to your pal. The monster's level drops to match your pal's player level, but the monster doesn't lose the accumulated exp. Give it some exp points and the level jumps. I haven't really examined this loop hole but it has happened to me a few times.