I just made the Binding of Ipos recently so I thought I'd throw in a few suggestions from my observations.
For Legendary Footfalls in general:
Currently it seems like if you have both mainhand and offhand legendaries you will only get the footfall for the mainhand legenary. It would be good if we can have both active at same time but not stacked on top of each other. Like when the character land with the right foot display the footfall for the main hand legendary and when the character land with the left foot display the footfall for the offhand legendary.
And as for the Binding of Ipos:
Would like more special animation in general. I have this one my Mesmer. Only the focus 5 got special animation. It would be good if we can have a dark purple line on the focus 4 skill instead of the standard white line that you get with any regular focus. And then when you press focus 4 a 2nd time would like a dark purple animation that collapses towards the centre of that focus pull. This will keep in line with the dark purple theme of this new legendary focus.
What do you guys think?