*Notes
(The following notes will apply to many builds both now and in the future)
First, when it comes to Regular Iso-8 builds there are always different options and everything from weapon or gadget choice to hero/armory bonuses factor in. Typically the one stat that you will want to avoid, when it comes to PvP at least, is stamina. I cannot even name the last match where I ran out of stamina or had any stamina issues whatsoever. The vast majority of this will be provided by bonuses, even if the hero appears to have low stamina, they will still be covered by your hero/armory bonus.
Second, evasion is not very valued or at least it hasn't been in PvP. Don't get me wrong I can see the extreme advantage in evading an enemy's attacks, but the problem lies in how this stat has been set up or managed and all the weapons, gadgets, and abilities that will completely ignore it. Unfortunately it has been under-powered and although I would love to try to implement a high evasion/dodge team, currently I just ignore this stat as you will most likely only avoid through special passives, buffs, and procs such as reality hacking.
Third, for a very long time I favored defense over health. Defense factors in on every hit (except those that ignore the defense stat, whether by type or adamantium, etc.) whereas health is a one time stop gap. If you get hit once or if you get hit for that little bit of extra health it will no longer be an advantage. This was especially a problem and still is to an extent with one shot abilities. Say Havok's Plasma Wave hits for 20k and you only have 16k normally and 18k with added health. You will get obliterated either way. However, with the level capped tournament and the numbers dialed down, having a bit more health can make quite a difference. Due to this change I am starting to use iso-8 which has a health boost more often and would recommend it a lot more now than I would have before. So as an added note, anytime you see bulky (attack and defense), feel free to change it to stalwart (health, attack, and defense).
Lastly, accuracy is something that can be very tricky. For one, it's difficult to decide how much you should add. As a point of consistency I max the bars (5) on most heroes and costumes. However, there are a few characters who don't need or rely on this stat. Also, there are items, passives, buffs that will give you things such as guaranteed hit. Gamora's movie alt is a great example, or the Dragon's Foot and Rectifier when it comes to the Agent's equipment. If you know you are going to provide guaranteed hit and have the silver to change iso-8 then drop accuracy out of the equation and pump attack, defense, (and maybe health as well). One very important final note that I want to emphasize is I nearly always would recommend attack first and never stop increasing this stat. That's just my own personal philosophy. The exceptions would be if you are either building a super tank - support character like say Rescue or if your team is purely relying on dots and debuffs.
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} Generalist's Empowered Trench
2 x Forceful
6 x Stalwart
Inspiring Empowered Iso-8
Weather Control Device
Twisted Gift
Neuropurge
Signpost
Enchantress
8 x Stalwart
Resonant Empowered Iso-8
L2 - Thorned Augmented Iso-8
Nul, Breaker of Worlds - Bruiser
5 x Forceful
3 x Bulky
L1 - Knocking Augmented Iso-8
L2 - Powerful Augmented Iso-8
L6 - Gracious Augmented Iso-8
L9 - Erupting Augmented Iso-8
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} Bruiser's Safeguard Suit
2 x Forceful
6 x Bulky
Vengeful Empowered Iso-8
Weather Control Device
Ex Oblivione
Gaunt Caress
No Mercy
Enchantress
8 x Stalwart
Resonant Empowered Iso-8
L2 - Thorned Augmented Iso-8
Beast, Horseman of Pestilence - Infiltrator
7 x Forceful
1 x Bulky
Reflexive Empowered Iso-8
L1 - Bloody Augmented Iso-8
L9 - Knocking Augmented Iso-8
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} Tactician's Empowered Armor
2 x Forceful
6 X Bulky
Quick Empowered Iso-8
Synthetic Cube
Ex Oblivione
Memento Mori
No Mercy
Enchantress
Resonant Empowered Iso-8
8 x Stalwart
L2 - Thorned Augmented Iso-8
Loki
My iso-8 build for him is outdated, but I would possibly go full Stalwart for him. Unless you would like to try some evasion stat boost, then perhaps Skillful.
Resonant Empowered Iso-8
Protective Empowered Iso-8
L1 - Sorcerous Augmented Iso-8
L2 - Thorned Augmented Iso-8
L6 - Aiming Augmented Iso-8
L9 - Bursting Augmented Is-8