Grand Summoners is a mobile phone video game app. It is an RPG game, and features the ability to summon heroes from other worlds and time periods to aid in battle.
In 2018, Grand Summoners announced their first collaboration with One-Punch Man. That year, Saitama, Tatsumaki, Genos and Boros all became summonable heroes, and in 2019, Fubuki, Garou, and Speed-o'-Sound Sonic also became summonable to celebrate the release of the second season of the One-Punch Man anime.
Already present since 2018, Saitama got an ultimate power boost for Season 2. He now has the potential to be one of the strongest fighters in Grand Summoners, making him invaluable against bosses. His costume comes as various equipment parts, such as Hero Gloves, Hero Boots, and Hero Cape. They provide unique bonuses specific to his own.
Terrible Tornado was never considered a tank, but she is making her way to be a must-need on the team. She provides excellent support by always paralyzing her opponents, boosting allies' abilities, increasing magic resistance and a deadly breaker. Tatsumaki's gear is obtainable prior to season 2, unlike Saitama.
Painfully accurate to reality, Genos has a hard time catching up to his Sensei. His stats are nearly the same as before, but his arms are now bonus equipment that deals blinding damage.
Finally, Fubuki gets to stand alongside her sister in battle. Fubuki has been placed as a water unit, and her powers are unique in such a way that she cannot be compared to Tatsumaki. Her main advantage is when she is placed against fire units. Ex: Her Coat, Necklace and Dress are available. They might just be slightly more desirable than Saitama's gear, not just because Fubuki is stylish, but are excellent to be used for water-type magic users.
He missed out on the first collaboration, but to atone he has entered Grand Summoners with tons of gear and critical damage. Accurate to the anime, Sonic doesn't have the same glamorous powers that others have. Similar to Terrible Tornado, he is definitely no tank. However, he dodges most damage barreling his way. He supports his allies via high defense and crippling damage on foes. His Mask, Katana, Scarf and Shuriken. They all add to damage evasion, critical, dark damage and arts gauge.
The Hero Killer makes his way onto the stage. He is not the first "Monster" to appear in Grand Summoners from One-Punch Man. Lord Boros had that honor in 2018. He is a slow build, but with promise. Possessing ally boosts by 50%, Dark damage, Decrease of opponent's accuracy and potentially 300% true art. He doesn't hit the ground running quite like Sonic, but could possibly outweigh him in damage dealt when maxed out. He does not come with any bonus gear.