@tosforfree
Alright so here is how magic amplification works. It gives a boost to magic attack from 0%~100% of the total magic amplification value. So I’ll use your values for example:
Your original weapon had a magic attack of 165. Consider the magic amplification 0 [no magic amplification]. So let’s say it did damage to enemies based on the formula given below:
{([Base magic attack + %base magic amplification] + [Total equipment Magic attack + %total equipment magic amplification] + skill bonuses) * weakness multipliers [elemental or stab/slash/hit] } - total enemy magic defense
And for this example let’s say it dealt about 300 damage to the enemy at a flat rate like you said. Now if you switch to your new weapon with 98 magic attack and a magic amplification of 180. This means that if you attack the same enemy over and over again you are going to see different results based on the random magic amplification done.
0% Magic Amplification: 98 Magic Attack + 0 = 98 Magic Attack. [New weapon]
0% Magic Amplification: 165 Magic Attack + 0 = 165 Magic Attack.[Old weapon]
100% Magic Amplification: 98 Magic Attack + 180 = 278 Magic Attack.[New weapon]
Damage done to enemy[new weapon]:
Damage to enemy[Old weapon] - (Total Magic Attack[Old weapon] - Total Magic Attack[New weapon])
0% Magic amplification[ New Weapon]: 300 - [160 - 98] = 300 - 300 - 62 = 238
100% Magic amplification[ New Weapon]: 300 - [160 - (98 + 180)] = 300 - [160 - 278] = 300 + 118 = 418
So now we see that with the new weapon we can get a attack of anywhere from 238~418 on the same enemy. The average attack is 328, so it is more beneficial for you to switch to the new weapon, even though it shows a lower Magical Attack!