I refer to this as the min-maxer's curse, though I'm sure it has other names.

 

I'll be honest, I don't use it very much. It's actually fairly annoying because if you lose 5 HP with a combo, you still have enough mana left over to heal the next attack with another combo and recover as much mana as possible. The only way it's actually useful is when you're trying to use 3 attack combos before your opponent has a chance to respond. If your combo is cancelled quickly enough, though, then you can still recover mana and use your attacks, but you'll have to use more of your combo mana because it is going to take a lot longer. If your combo combos aren't blocked and you're forced to use it when your opponent responds, it's only going to result in more than one attack combo being used, which will make things very messy; which is why you don't really ever just use it to burst the opponent down, but instead, use it as another way to build up more energy for your combo. The key is to keep using it to create mana in your attack combos if possible (which is generally easier said than done) which will give you enough time to combo the opponent after your last attack combo.

Mana Drain [x2] is a spell you can cast on an Attack combo or in response to an incoming attack. By doing so, she basically drains any remaining mana remaining by that attack, which you can then recover without using mana again. She's one of those spells that can be very useful in a combo depending on what the enemy team needs to do. For example, if one player has 5 attack combos and one needs to finish them off with the rest of the team, you know that the player you control with the Mana Drain is the player that's most likely going to be able to counter the enemy team with the last turn of their attack combo, since they'd probably want to finish off the team without having Mana Drain, while the one you choose will make it unlikely that they'll be able to combo (because they'll have the chance to combo again) once it's over. This isn't always true though...

Note : If the effect of Mana Drain is negated by another effect, even if it doesn't prevent the enemy with the most mana from doing any damage at all (even if they have the effect to reduce the damage that damage could deal), the player will still be able to respond with more damage to their opponent! So this is useful for the team with the high mana drain who needs to deal more damage in