Gambit Is Constantly Changing In and Out of His Costume

Here Gambit tries to use his Thief Extraordinaire every turn to tamp down threat and scope out the Encounter Deck. Let your allies do most the attacks against enemies, but don't hesitate to take shots at multiple targets in your Gambit identity.

Do Lots of Stuff in Alter Ego

• get X-Gene onto the table (use freely thereafter)
• use Mutant Education to recycle Molecular Acceleration or other hero cards
• heal allies with X-Mansion
• confuse the villain with Creole Charmer while removing threat
• remove more threat with Remy's thwart action, which exhausts your identity
• remove more threat with the Guild
• draw a free card from Moira MacTaggert when you flip out of Alter Ego
• budget your cards based on what you do in one form, then flip in/out of Alter Ego and play the others

Prevent the Villain from Scheming

If you spend the whole game in Alter Ego the threat level might get out of hand. So use Gambit's Guild Armor to defend on alternating turns. If you manage to reduce the damage to zero you get to ready Gambit and go about your business. Warning and Natural Agility can help pull that off.

Mow Down Multiple Enemies

Use Melee and Royal Flush to initiate attacks against multiple targets. Then use Gambit's charge counters (and up to one counter from Warrior Skill) to add 1-4 damage to each target. Contrast these against cards like Slice and Dice which have multiple separate attacks and benefit less.

Persistent Allies

Allies should generally attack every round to benefit from Boot Camp, X-Mansion, Sidearms, and Attack Training

Cosmo takes no consequential damage when you know the top card of the Encounter Deck, which you can do every turn

Wolverine heals slowly but can be sped up by the X-Mansion

Brawn can't heal... but with 5 health he sure gets a lot of benefit from Boot Camp before he's defeated.

If you save up charge counters, Rogue is cheap and can lay down quite a bit of hurt. Even moreso with Attack Training

Other Cards to Consider

• know there will be lots of minions? War Room, Hall of Heroes, and Into the Fray will all pay off
• Surprise Attack could work out with all of the flipping out of Alter Ego
• if you like Brawn then you'd love Sentry
• Aggressive Energy could further boost the multi-attacks, but holding cards between turns isn't great
• Energy Spear and Enraged can make Cosmo into quite a beast, but the combo relies on Cosmo being drawn and played before the upgrades.
• The X-Jet helps you long-term in exchange for a one-turn tempo hit, but we already have X-Gene and Martial Prowess for economy

Good luck, please comment here with any feedback and ideas!