All the nerfs made him utterly useless and subpar to other tanks.
2 ward nerfs they once blocked 300 dmg each[Edit] (corrected to 300) now only block a tiny 58 dmg
health nerf yet he’s labled a tank and has the lowest for one
plasma dash stun is 1 sec ISIC can’t escape melee characters now since they get up so fast
slow removed and replaced with heal debuff on lvl 5 mutation( which doesn’t even last long)
Omega Strike the ultimate nerf only allowing 40 sec of use
The first ward nerf I could live with but the second one shoot, now its doen’t block jack sh*t for dmg forcing you to overcharge even then an overcharged ward doesn’t block enough dmg some characters can deal more than 50-100 dmg in just 2 secs
Health nerf was also uncalled for makes ISIC untanky to have such low HP Kleese got a HP buff an it almost matches ISICs base HP. That’s a problem because Kleese is NOT a tank. Every other tank has a base HP of 1900 to 2200 and they tank using Life steal(Attikus) HP regen/Dmg reduction(Boldur&Montana) HP stacking(Kelvin) and active blocking (Galilea) all are supperior to ISIC methood of ward and shield stacking.
ISIC has a shield that blocks yes but is counter intuitive to his play style when at range you want to deal as much dmg as possible  (to generate threat) and your wards are suppose to be your “shield” blocking bullets and arrows is a waste of time eventually they will break the shield and dmg you and you’ll have no defenses, as for melee characters oh boy holding that shield up is just delaying your inevitable death since you have limited escape options since they stun on dash is one sec now it doesn’t take long for quick characters like phoebe and rath to get up an continue wreking you.
The lvl 5 mutation nerf also makes ISIC useless against melee characters. The slow wasn’t used to shoot targets easier(that’s the case with me and other ISIC mains) it was made (imo) to counter melee characters slowing them makes it easier to kite them since you are huge and slow.
(I would’ve liked to at least have the wound debuff last a significant amout if time instead if 1 sec)
Nerfing the ULT makes no sense either if it was because of PVE then I can somewhat understand, but if it was a PVP problem then the nerf was uncalled for.
ISIC is extremely exposed when he’s in omega strike he moves very slow and cannot use his defensive options like wards and dash he puts out a lot of dmg but can be focused rather quickly if you coordinate your team you can kill him in the ult through focused fire and stuns (looking at you Rath and Alani)
ISIC was once a formidable machine of death order and destruction, now? Hes just a slow walking squishy gun turrent he’s not a tank at all just a disrupter.
[Edit for grammatical and rhetorical errors]
[Edited OP to extend more opinions]