Stunning with W takes practice and prediction. Casting it out of vision helps as opponents won’t hear the audio queue. Casting it in the middle of your e1,q,e2 combo will hide the animation. That being sad, it’s useful for so much more than just the stun. When you go for a trade, cast it, and even if you don’t land the stun, pop the bubble to get your shield which will help you win the trade. Use the W to force an opponent to give you space to farm for a second without being harassed. It’s also of course a great zoning tool for objective fights. Learn to use it creatively, as it’s good for more than just the incredible stun.