You said in your original comment:

How can NK design a paragon to make it better than the 5xx! (Damage wise at least).

Which means that you asked how they could make it better than the t5 sentry champion, to which I replied that being better than the t5 isn't a necessity for paragons. You never mentioned support or balance in your original comment.

I guess balancing it to be a boss damager and support could be done the same way they made it for the ninja paragon or the buccaneer paragon. Either a permanent small attack speed buff for all towers, or an ability that buffs attack speed significantly for one tower. The sentries should be very strong since they can't be buffed by external sources, but I have no idea how the trap could be made different from the t5 XXXL trap unless they make it capable of absorbing BADs, which would be absolutely broken.