Bottom Line Up Front:

Kingpin and Red Mags can handle most of these fights.

If you bring Kitty (Moleman and Zemo fights) and can bring Tigra for the fights then it's a lot easier.

Fight 1: VenomPool (Cosmic)

Occult Immunity - Heavy: VP is immune to Nullify, Stagger, and Fateseal. Knocking him down disables the immunity for 15 seconds.
Enhanced Parry - Armor Up: Each time you Parry him, he gets an Armor Up Buff for 15 seconds. Does not stack.
Scared Stiff: Ever 8 seconds you are Rooted for 4 Seconds. The timer is paused while you are doing a Special Attack and it is reset when you land a hit: so be aggressive.
Arrogance: Every 10 hits on your combo meter gives you a Falter Passive for 3 seconds. When you are struck it is removed.
Contagion: Whenever VP is struck or when he blocks an attack there is a 30% chance you will get a Poison for 10 seconds dealing 100% of his attack to you.

Fight 2: Moleman (Skill)

Special 1 Bias: Will throw SP1 more often.
Shock Tether: If either champ has not made contact in 6 seconds both champs get a shock Debuff.
Heavy-Hitter: He is unstoppable during Heavy Attacks- and it lasts a beat after it's over- so don't rush in.
Fight or Flight: He gets an Unstoppable Buff every 12 seconds and it lasts 4 seconds. If you are far away- you get the Unstoppable.
Chum the Waters: Whenever you Dodge an Attack, both champs get a Heal Block Debuff, a Taunt, and a Disorient for 12 seconds.

Fractured Guard: You gain a permanent Armor Break Debuff when you block one of his attacks. When you throw a Special it removes one Armor Break from you per Bar of Power consumed in your Special.
Redlining: If you go above 33% of your Max Power you gain a Power Gain Passive which increases your Power Gain. If you go above 75% of your Max Power you are immediately Power Drained to zero.
Toxic Thoughts: If you Parry him both of you get a Poison that does 1% damage over 6 seconds. If you are Poison Immune you get a burst of Direct Damage of the same amount.
Languor: If your Power drops to 0 you take a burst of +240% of the Defenders Attack as Direct Damage. (See above Redlining node).
Encroaching Stun: Every 20 seconds you get Stunned for 3 seconds unless you are performing an SP1 or SP2 when the timer expires.

Ebb & Flow - Intercept: He has Protection. You can take it down by Intercepting him. You also get a Fury Passive when you intercept for 12 seconds. After the Fury expires the Protection returns and all Debuffs on him are Purified.
Repeat Offender - Taunt: Landing the same type of Basic Attack in a row inflicts a Taunt on him for 3 seconds.
Enhanced Special 2: His SP2 does more damage and the first part is Unblockable.
Wavering Will - Intercept: You can't reduce his Ability Accuracy. intercepting him disables this for 10 seconds.
Stay Awhile and Listen (Passive): When you get Rooted you are also Special Locked for 3 seconds.

Attacker Special Burst Lock Down: When you launch a Special Iron man is inflicted with a Heal Block and an Armor Break Debuff for 5 seconds.
Enhanced Special 1: His SP1 does more damage and the first part is Unblockable.
Combo Up: His Combo Meter increases by 1 each second unless you Intercept him. Then it's paused for 10 seconds.
Obstinate Charge: He is Stun Immune on his first attack. This goes on cooldown for 8 seconds if you Parry him, but not on the original Parry- he will be Stun Immune for that.
The Walls Are Closing In: You get 10 Tactus Charges when the fight starts and a 30 second timer begins. Each second that either of you are backed against the wall it reduces the Tactus Charges by 1. If the Charges are not at 0 when the 30 seconds are up then you take Degen dealing 30% of your Max Health over 5 seconds. When the Timer expires, the 30 seconds starts over and the Tactus Charges are reset.

No Hit-M...ercy (Buff): Each time you knock him down he gains a Cruelty Buff giving him extra Crit Damage for 10 seconds. While he has the Cruelty he can Crit into your Block.
Now You See Me: Every 8 Seconds you get a Falter for 3 seconds. The timer resets each time you land a hit.
Steady Perseverance: When he launches a Special Attack, he gets a Stun Immune Buff for 4 seconds plus 2 seconds for each of his Unique Buffs. This Buff is paused during his Special Attacks.
Debilitate: Any Debuff he puts on you has +100% duration.
Long Distance Infinity: When he is far away from you- his Cruelty, Unstoppable, Vigilance, and Indestructible Buffs are paused.

Doom Slap
Kitty
Rintrah
Symbiote Supreme
Silk
Absorbing Man
Longshot
Hulkling
BWCV: just need to manage the falter timer and the fight is a breeze thanks to her applying buff immunity and her immunity to incinerate if his SP2 is an issue for you.