The brella feels a little too slow to play super aggressive with. It has really fast movement/wall climbing so it's good for flanking, but direct combat is difficult against higher ranged weapons. Point blank shots deal 90 damage while longer ranged shots can do as little as 10-15 damage which kinda forces you to approach/retreat in most cases. If you try to approach and they just shoot while retreating there is not really anything you can do other than back off or shoot your umbrella at them lol.
With that said, I think this weapon truly shines as a supportive weapon. It has a ton of utility since it can block basically anything thrown at it. Blocking charger shots while riding the tower in Tower Control, defending your partners super jump in, blocking tenta missiles, ink jet, bomb rush and all the regular bomb subs, and pretty much anything else that would normally force you to retreat and lose ground control. I've already found myself fearless of tenta missiles, chargers, and flinging rollers. The mobile shield by launching the umbrella is really fun also! I have not found any amazing uses for it yet, but at the very least it's a low commitment for free pressure on the opponents and one of the only range options we have. I've already landed a couple of surprise kills with it and I think it would be incredible for pushing people into water since it has a decent amount of knock back.