QUOTE(Scremaz @ Aug 5 2016, 02:49)

if it's useless, then why keep it? just for the sake of filling the 3rd slot? 95% of time you won't use it - and it will only eat mana - and the remaining 5% you can still cast it by hand/scroll.
Let's assume we are talking 1h.
While not strictly necessary spark let you set a low minimum hp, that let you cure less and in general be more efficient.
It also prevents unlucky rounds (5-6 spirit attacks together can easily decimate your health).
If I had to choose one spell to remove I would honestly remove spirit shield.
The higher level/forge you go the less it kicks in, and in normal arenas I prefer losing HPs than spirit points.
But then you would need to switch IA for FSM, or if you remove spark you have to put it on when you do IW and the list goes on.
Honestly is much easier to just keep the usual combination, a little mana cost is nothing.