Army of Ruin

There's a decent chance this will come naturally, because the difficulty in this game doesn't drop off as fast as it does in Vampire Survivors, and it's pretty easy to get overwhelmed even on early stages if you don't have a good build or many upgrades yet. However, you can very quickly grind out these achievements for dying just to unlock the trinkets they give you, and it only takes a couple minutes total to load into a level and stand on an enemy until you die. Then, retry and repeat.

I actually don't think it's a bad idea to grind this out earlier rather than later, because the Soul Container is actually a really good item, giving you extra lives and extra damage when you respawn. The only downside is that its element type isn't very useful.