Pain offering gamepad problem

The ability is a must have but with gamepad i need to spam that for cast the spell, consume a lot of mana and were a big problem if would use the skill support gem Ablation cuz requires 15 % of my life.
With gamepad this spell don't cast really well, if i spam the button 4 time when i look at my minion that spell cast 1/2 time ( after the buff disappear obviusly )