There is not, although generally you shouldn't want to disable that as it provides a solid boost to progression. For the particular case of heroes surviving longer than you'd want them to, I'd suggest to adjust your base hero stats to focus on damage
i finally had 75 shards to do the daily mission, and my game lagged out when i opened all hero packs and tried to buy another, ended up losing both packs.
is there something I am missing to open unclaimed hero packs?
There is no prestige in the game, but we'll be making an update in a little bit that will give you a bonus (to health and damage) based on the Skill Points you've spent that should help with that a little bit. Just as a reminder, make sure to spend your GodPower in the Divinity tab, Craft Armor to gain strength, spend skill points, and keep at least a little Favor in your Gods so that you can get their bonuses :).
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There is not, although generally you shouldn't want to disable that as it provides a solid boost to progression. For the particular case of heroes surviving longer than you'd want them to, I'd suggest to adjust your base hero stats to focus on damage