Marvel's Midnight Suns

I got this one in the final mission in the game in this mission you get all the legendary cards unlocked so you don’t have to grind out everyone’s friendships plus you get a lot of heroism increases so just save up and use three different legendary abilities which are the gold cards
Good luck and happy hunting!

You can get this at about the halfway point of the game if you’ve been targeting two specific characters for MAX friendship first.

In my instance, I targeted Blade and Ghost Rider as they were both available early on.

Once you max your preferred two characters friendship, they will have a Midnight Sun Challenge made available which upon completion, will reward a Legendary Tier Card and the Midnight Suns Suit unique to the character.

You will also have to complete Hunter’s Midnight Sun Challenge, which is the first one that will be made available (refer to the achievement for a guide on this one if you need it as well).

Slot them into the decks of each character and go on a general mission with the 3 characters (one of your two maxed ones must be a mission leader for that to happen, you may get unlucky and have to retry the following in-game day.).

Keep dragging the mission on until all 3 cards roll onto the deck, use redraws one pointless cards, AVOID using your Heroism as each Legendary card should require at least 4 Heroism to use. I just played the “Defeat Enemies” general mission and didn’t kill the last one or two enemies on a turn to cause more to spawn. I done it on the first attempt.

Once you draw each characters legendary card, you’ll earn the achievement. DO NOT use a duplicate card if it ends up rolling on the deck, they must be different legendary cards.

Use the T.H.R.E.A.T. room. I used captain marvel whose legendary ability cost 2 heroism. Then I put venom and wolverine on the team. Venom’s legendary doesn’t cost any heroism and wolverine’s cost whatever heroism you have. As long as you have 1 heroism at the start of your turn you should be fine because venom’s legendary gives you 2 heroism.