There is a reason: you have limited party slots. It’s better to just use Thaum and get another caster in the party.
I agree it is a good skill by itself which can potentially be used in several ways, but getting 3 circles for it never worth it. You can get priest 3 instead and get revive and mass heal. Or you can get Paladin and get Barrier and lots of useful buffs (and triple damage vs demons smite).
Other Sadhu skills are not superb either, so going for circle 3 is really a pain. If they added at least one or two new skills, then it might’ve worth it. But in current state Sadhu is out of viability.
Every other cleric class right now is better then Sadhu after all the nerfs he suffered.
I’m not sure what difference in damage you are talking about. In video you posted above I already explained where the difference came from.
Magic ampl is the same as maximum magic damage. Simply talking, it improves your max matk. And it is multiplied by T1,T2,T3 and enchancement so it can result in pretty big variation (for example in this video T2 is 2 and enchance is 1.65, so his magic ampl is multiplied by 3.3)
This is exactly the result of magic ampl: it imroves the highest damage skill can deal. So the damage range becomes larger.
Actually it’s explained in the thread you posted. You just misunderstood the explanation probably. For example we have a 3 damage multiplier (attribute/damage type/etc).
If we have 100 matk, and 200 magic ampl. Then you can deal any amount from 300 to 900. So it basically improves max magic attack. Average damage becomes (300+900)/2=600. So 200 magic ampl simply adds 100*3=300 magic damage, or 100 magic attack.
The same applies to Zalciai. But lets assume we have 1000 matk. Then with 48 magic ampl we will have 1048 max magic attack. So average would be 1024. Sure it’s not 0, but you won’t feel it at all when your skill deals 2k damage. So in most situations it’s better to NOT cast Zalciai and do 1 autoattack instead.
Talking about late game monsters, that’s exactly what I mean. Invseting in Zaibas you will make your late game weaker, because you will have less skillpoints for useful skills. As the game progresses Aukuras becomes much more useful, as it more then quadruples your HP regen. And Zaibas will do NOTHING in Earth tower and future content, because it’s not even AoE, it will just deal 14 hits split between mobs and stop no matter what.
And Magic amplification from Zalciai becomes useless already at level 200. And yes, it’s totally possible to get 300-500 damage split if you have maxed multiplier and hit ice attribute enemies. (300~300+4822)=(300~492). So yeah, it’s pretty useful at low levels.
Just remember that by chosing skills that weaken your end game over potentially strong end game skills you permanently make your character weaker.