Helios' abilities don't have any cost related to them, so the use of his abilities is only limited by cooldowns. Instead, he uses heat as his secondary bar. Helios starts with 0 heat, and it caps at 100.
Helios' autoattakcs generate 10 Heat, while his abilities generate 20 Heat. When Helios reaches 100 Heat, his abilities become supercharged for 5 seconds, dealing 10% increased damage and applying his passive to all enemies hit. Once 5 seconds have past after his last spell cast, Heat starts to decay at a rate of 5 per second.