Wasp loves this, alongside ATK buffers like Combat Training, Aggressive Conditioning and Combat Specialist! In that combo she could potentially get rid of up to 11 Tough status cards on enemies, and that's before counting in any Giant Strengths.

Extremely inexpensive way to redirect an attack onto yourself, trigger any defense-related cards like Flow Like Water or Electrostatic Armor, and also plays into Excelsior and Change of Fortune really well!

Highly character- and scenario-dependent card, it can trivialise some enemies. Notable characters who can use it well would include Rogue and Cyclops, as they can consistently put upgrades on minions, though you can always help yourself with Air Cover.

It provides a very easy way to defeat minions like (the list is not exhaustive, just some examples to keep in mind):

Those who hinder your ability to attack or damage them:

-Blob 3.14 (who otherwise can only take 2 damage from each attack)

-Edison's Giant Robot (can't take damage until a resource is spent)

-Thomas Edison (can't take damage if you're engaged with other minions)

-Sebastian Shaw (can be attacked only once per phase, gets tough cards easily)

Those who simply have a lot of HP:

-Brothers Grimm (8HP)

-Badoon Headhunter and Headhunter's Henchman (7 and 8 HP respectively)

-Sentinel Mark VIII (8 HP)

-Tombstone (9HP)

Those who have nasty effects on being defeated or taking damage:

-Sandman (Iron Spider's Sinister Six, has you discard cards after getting damaged by an attack)

-Shifting Apparition (shuffles encounter cards into your deck if you defeat it with excess damage)

-Delgado (gives the villain a boost card and clears their stuns and confuses)

-Embassy Guard/Patrol (puts 1 threat on Batroc's Alert Level)

-Hydra Soldier (gives the engaged player an encounter card)

-Madame Masque (triggers The Hood's Foul Play ability)

-Zero (conditionally shuffles itself back into the deck)

-Orion (gets a tough status card after being damaged)

A great card that makes basic attackers more viable. Alongside Combat Training and Combat Specialist you can get +3 ATK with +3 HP which is something characters like Quicksilver or X-23 would absolutely love. Not only it's more value than Combat Training and Endurance (the benefits are the same, but at 1 ER cheaper), but it can also be stacked with both of those.

If you are building a red deck with many ways to increase your attack, like combat training, specialized training, symbiote suit, now Im mad, aggressive conditioning. You can make this card get some great value eventually. I don't think its a very good card, but in some builds it can become a heavy hitter, effectively letting you get the effect of a ready for a 2 cost card if you were going to attack anyway.

Think like Ant Man, go giant form, gain 5 attack from your 2 upgrades in his base deck. Then another +5 from the upgrades listed above, you are now 10 attack. 2 cost event for 10 damage will end games fast. The above cards some are good enough to play on their own, others are a bit crap but still. In a build doing this stuff anyway, it's decent.