I have been playing Marvel Puzzle Quest: Dark Reign. Black Widow is an unexpectedly amazing support hero to have on your team throughout the early and mid-game. Marvel Puzzle Quest effectively uses health as an energy mechanic. Therefore, healing and damage reduction are really great things to have: they let you win the round and then they let you play more rounds.
Marvel Puzzle Quest rates its heroes by stars, with more stars meaning a rarer, more expensive, and usually better hero (and they have higher level caps). Black Widow is available in one-star (modern costume), two-star (original costume), and three-star (gray suit) versions. You cannot have more than one of the same character on your team.
Modern Black Widow comes with a great stun. Once you fully upgrade it, it stuns one target for 5 turns and the rest of their team for 1 turn. It costs 9 blue, which is three blue matches, so you can potentially keep someone stunned indefinitely if blues keep falling. This is especially great because of the game’s tendency to have asynchronous PvP rounds with one super-buffed NPC on your side. Have the NPC tank and deal damage, pick off the opposing non-buffed characters, then paralyze the enemy for the rest of the fight.
When you advance to two-star play, the new Black Widow has a heal instead of a stun (that also increases timers, mostly a PvE benefit). The heal affects your whole team, and it is rather strong. Marvel Puzzle Quest recently did an event with super-buffed Black Widows, so one heal effectively refilled your entire team. This is especially great because you can pick which of the enemy you are targeting, while which hero is tanking for you is dependent on what colors you match. You can spread the damage around your team and pop the big AE heal just before finishing off the last enemy.
Once you get to three stars, Spider-Man takes both support roles with both a stun and a heal (and a defense buff), while gray suit Widow is a damage dealer. Building a good Spider-Man looks like one of the milestones on your path to the endgame. Damage gives big, sexy numbers, but support wins games and wins the war.