Look for a small symbol on the right side of the card, between the illustration and the text box
The card is a dual land, allowing you to tap it for either green or blue mana, offering diversity over single colored lands and allowing for more color combinations in your deck
Another possibility for Hulk growing stronger is your opponent attempting to deal spell damage to him, but you negating it in the form of casting a spell that grants Indestructible, something easily found in the green card pool
Battle of Wits Although it's always been a meme, there were people playing Modern leagues time ago with Battle of Wits decks
One running theme, however, is that each of the Fantastic Four cards has a supplementary ability that can be activated for one white, one blue, one red, and one green mana, but each ability is typical of the base color of the card
If you want to read the associated article, just put Bennie Smith and the commander name into Google and it should pop right up