This isn't a list of the best defenders - this is a list of Underrated defenders which should be used more in War. I know most of these champs are already used but it doesn't hurt to to say they can be a pain to verse sometimes.
1. Cable - I hate versing this dude, absolute aggressive A.I, far reaching heavy attack, all special attacks are not hard, but annoying to avoid. I particularly just block his Sp1 as Kabam refuses to fix the bug in the animations (let me know if anyone else experiences his) its like you're evading half of it okay then all in sudden you get hit by the other half. Feels for the Duped starlord players. Regen can get in the way especially when your trying to end him in Aq with a champion who doesn't hit very hard. and then theres the power flood which is very odd how it works and activates so randomly you have little time to react and control it, this ability can catch many people off guard, not to mention that it is also stackable. Don't bring champions who inflict bleed or you'll suffer! even though many champions inflict bleed this will narrow who you use against him. his animations are very aggressive and he throws that heavy if you keep a block on him and if you have a fair bit of power and you forgot to bring a robot champion - jokes on you. That degen is annoying. what bothers me most about him is that he isnt half as decent as an attacker, hes a pure defender. that pretty much raps up Cable, if this was personal i could write a whole book about how much i hate versing cable. in other words... well done Kabam you got me there!
2.Punisher - I swear he's a villain, i still cant get over the fact that his tag says his a hero! even though I know he's storyline and everything- he's evil! Again all specials are hard if not impossible to evade without a starky or nightcralwer. is it just me or is he's Sp2 the hardest one to avoid? he's moderately aggressive, physical resistance...i don't understand whether it even does anything and then there's the sp3 which yes i have been gutted with before...we're not all legends sadly

3. Green Goblin - Sp1 just block, sp2 hope for the best and time well otherwise its a KO most of time. Debuffs take a chunk out of your champions though I've learned its best to block and take the block damage. also if you've read about him, you deal less damage at some stages of versing him (i could be mistaken for another champion, dont quote me on it), Regen doesn't usually effect me because i use my r3 5 star Angela often but it has caught me in war a few times on the +150% regen node.
4. Punisher 2099 - I'm slowly adapting to this guy, but it counts to say he deals a lot of damage through the block when you verse him in Uncollected mode. All his special attacks are hard to avoid but slow enough for you to parry the damage. I really love his mechanics but only when I'm using him not versing him, like the heal block. it can be a bugger when ur tryna top up your health. and if you read about this guy, under certain circumtances you have -90% reduced power gain.
5. War Machine - his Sp1 pulls him a lot as a defender, i dont know if anyone finds this but none of it is evadable so i just block becuase everytime i attempt to evade the last bit i get clipped . he also has an aggressive A.I like all the other iron mans. his sp2 is quite easy to evade, his armour gets in the way sometimes but can also kill him (especially when duped) with a Voodoo.
let me know in the comments who you guys find find to verse thats not classed as a defender or isnt in the top tier for defending.