The Warmind Cell is sort of a secret weapon in Destiny 2, capable of wreaking havoc among your enemies, but it still seems like something that many players don't know much about.
With the right mix of weapons and mods, enemies have the ability to drop a Warmind cell to death. You can then shoot this glowing orange orb and it will explode, dealing massive damage to enemies in a huge radius. It's actually pretty ridiculous to completely clean the rooms from low-level enemies if you're lucky.
For this synergy to work, you'll need a Seventh Seraph weapon, or the new IKELOS SMG 2.0 Spirit, which was brought back to the game with the Arrivals Season. You can get this weapon from Shadow Engrams. You will also need a Warmind Cell mod. The one you'll likely already have is Global Reach, a Gauntlet mod that was automatically unlocked for all players last season.
Equip the Warmind Cell mod and start killing things with your Seventh Seraph weapon, and watch the easy kills stack up when those Warmind Cells start to drop. The damage they do is enough to easily kill smaller enemies, and he also seems to ignore walls and cover for now, although that's bound to change in a future update.
If you don't have Warmind Cell mods, you will need to register with Banshee at the Tower every day as he can sell them sometimes, and they are really a must-have due to how strong that synergy is in the game now.