This power-up is more useful to Darius and Shaw than Tess and Toki.
With Darius and Shaw, this lets them use their offensive hero powers to keep the pressure on their enemies while still having enough mana to bring out their heavy hitters or big walls, like Tyrantus or Sleepy Dragon. Bringing out a lot of big minions is helpful against Lord Godfrey in particular since his pistol barrage makes mince-meat of smaller minions.
-Witchwood Monster Hunt-
This power-up is more useful to Darius and Shaw than Tess and Toki.
With Darius and Shaw, this lets them use their offensive hero powers to keep the pressure on their enemies while still having enough mana to bring out their heavy hitters or big walls, like Tyrantus or Sleepy Dragon. Bringing out a lot of big minions is helpful against Lord Godfrey in particular since his pistol barrage makes mince-meat of smaller minions.