Storm Giant Stats
Storm giants are generally good guys, and they won’t fight unless they have no other choice. When they do, their go-to is Lightning Strike, a highly damaging area-effect attack with a 10-foot radius. Because of the radius, they greatly prefer to hurl it where they can strike two or more enemies with it at once, but they won’t pass it up if they can’t, because even against just one target it still does more damage than two Greatsword hits. Like most other giants, they prefer melee attacks over throwing rocks, and they only do the latter when there’s no reachable melee target and Lightning Strike is still recharging.
Their spell repertoire is entirely cosmetic, except for control weather—as mentioned above, not usable in combat because of its 10-minute casting time. Storm giants (and cloud giants as well) cast and sustain control weather in order to set up the conditions in which combatants will find themselves. Most likely, they’ll choose torrential rain and either a strong wind, a gale, or a storm. This combination imposes disadvantage on all ranged attack rolls and on Wisdom (Perception) checks that rely on sight or hearing, douses open flames such as torches, and inhibits flying, requiring airborne creatures to touch down at the end of each turn or fall out of the sky (“Wilderness Survival: Weather,” Dungeon Master’s Guide, chapter 5). If they aren’t anticipating a fight but simply want to confuse trespassers, they may instead prefer to blanket the entire area in heavy fog, effectively blinding everyone in it. (TMKWTD)