Any pro Isis players out there?

She looks very fun to play, but I have a tough time with the Ult and I can never seem to land the 3 when I need it.

I am not a pro but I sometimes play Isis. First of all it is hard to hit 3 at max range because it is slow, so easily avoidable. Although you can detonate it at any time unless you know.
Her ult is great in teamfights. It can deal a lot of damage and heal your team mates and yourself. Although it is hard to place it. I try to place it in narrow jungle paths, near objectives ( help me secure them ).
Just practice playing her and you will be able to hit your 3 more and more. But it is harder to hit it if you have high ping :D

Hope I helped a bit

The thing about Isis is that you have to be able to predict where your opponent will be and also to know when to fire your spirit ball, if your enemy looks like they are committed to doing a move that is an excellent time to fire a ball at them as they are probably over-focused on the ground targeted rather than the incoming ball. Another great time to fire it is when they turn there back as they probAbly won't be able to turn then react in time to avoid it... Or through walls through walls is cruel and unusual as all the sudden a wild explosion appears and chunks out over a quarter of there health, with her ult use it as a counter tool... Like Anubis ults you then drop it so your both in the ring to charge it faster... Use her ultimate to force people to make choices do I keep chasing this poor Bakasura and finish him off or do I back off. When people get to greedy is when you get the kills off of it ususually. Use her ult to contest objectives, like say you have you and a teammate trying to get a tower and 3 enemies gank out of no where through down her ult and make them choose do I jump in there and try to kill them or do I let them take the tower. Often time they will jump in you guys fight the tower and them till your hot is charged boom you detonate it and nearly kill them all, while heing you and your teamate they run away you take the tower anyway maybe scooping a kill or two.

I am not a pro I just enjoy killing everyone as isis

Psiyo is a great isis player.