Hello, well the Event Tick is an update event. I made a solution for your question using the animation inside the widget, i think its easier and only need a few nodes =p.
1- I created a text and made an animation of its oppacity from 0 - 1 - 0, like the follow image:
2- I went to event graph and when my widget is created i will play an animation and choose the animation i created, also to make it loop forever i changed the parameter “Num loops to play” to 0, if you wanna play this animation a limited number of times, you are free to do that. The follow image shows what i did on graph: