This commander sets up ugly board states where you have a Bitterblossom trigger in your upkeep, some planeswalkers that make something during your main phase, a Veteran Soldier in combat, and youre suddenly drawing 10 cards a turn while presenting a lethal strike force
The better versions have a wincon or two like Thassa's Oracle when you get decked, or Aetherflux Reservoir
Darksteel Forge Imagine a counterspell, except it, disappoints everything constantly
The strategy involves filling your graveyard with key cards to enhance Kathril's abilities, while also controlling the board with removal and protection
Wrenn and Six Prior to Wrenn and Seven and even Wrenn and Realmbreaker was Wrenn and Six, a powerful Red and Green planeswalker that was banned from the Legacy format
The thing is that Squee, the Immortal can be cast from your graveyard or from exile, meaning that with just these two cards, you already have an infinite mana combo - all you need is an outlet for it