Phan'Thul's abilities have no cost related to them, and the use of his abilities is only limited by cooldowns. Instead (Like Rumbler), he uses Heat as his secondary resource. Phan'Thul starts with 0 Heat, and it caps at 100.
Phan'Thul's basic abilities generate 20 Heat when used. When Phan'Thul reaches 50 Heat, he is in the Danger Zone, causing all his basic skills to have enhanced effects. When Phan'Thul reaches 100 Heat he overheats for 6 seconds; during this time he may not use his own abilities, but all his basic attacks deal physical damage over time. While not overheated, after 4 seconds of not using his basic abilities he will start losing Heat at a rate of 10 Heat per second, then a rate of 20 Heat per second 2.5 seconds later.