Until 100 arcane power is really decent skill. Wizard spirit gives decent bonuses on next lvls also it shortens reuse of the skill. But on the lvls 85-100 it's definitely better.
Maximizes magic efficiency by increasing M. Atk. by 30% and MP Consumption by 10%. Every second, 50 HP is consumed. vs 3 of the lvl. Magician. Atk + 50%, P. Def. Def. + 50%, Magical. Crete. Attack + 50% +
You got it wrong. You're comparing arcane power to new wizard spirit toggle. I said that normal wizard spirit + class passive(that you won't learn if u have arcane power) are better togheter than arcane power itself, IMO. And about new wizard spirit toggle, it gives m attack, p def, magic critical rate and consumes mana. Old WS gives p/m def and no mana tickles.