it’s a trade off… +90% Weaken (Crystal) and Effective Mythic is a good combo that takes up 2 spaces, the only weakness being Greatly Resist on the right Element and same for Immune to Map Element. Ignore Resist only takes up 1 space and ignores enemy resistances and immunities at the cost of not doing Effective damage.
one thing I haven’t done is compare +90% Weaken & Effective Mythic vs. +120% Weaken (Weaken Cap is +200%. 2 Crystals & 1 Epic or Mythstone takes 3 spaces). they both take up 2 spaces. I think I will do the math for this soon and post it. I’ll also do a comparison with Ignore Resist.
here’s Mid’s 3.0 Guide on the subject. now, he puts Ignore Resist last because most enemies wont be Greatly Resist or Immune to the correct Element to weaken Effective Mythic. but the ones that are are usually the Epic+ monsters with tons of HP and 3 to 6 monster affixes. in the end, 1 space with +90% Weaken is best, 2 spaces with +120% Weaken is next best, and after that, it depends on what you want your build to do and how much space you need to make it all work.
Skilled Mythic stays with the Primary Skill when using Discordance (it follows Boomerang, for example), so it wouldn’t work with the Special when getting switched. on the other hand, Mutli Attack & Extra Attack Chance will switch over to the Special Skill, which is a huge boost to damage/dps for the Twister. putting Twister +10 on the Pet will boost your Twister just like for a Wizard. if you’re willing to give up 2 more spaces, you could put +5 All Skills on your Weapons and get Twister +20. this will increase your Twister damage +100%, increase AoE by +20%, and the Twister’s Attack Frequency will be 4.8 a second for 5 seconds (the duration of Twister) for 24 attacks total.