Wargreymon

Wargreymon’s effect will cease to function when you have no more security cards to tap from, and can be dangerous when used without any means of recovery. [BT2-039] Magnadramon is a solid choice as, while expensive, will allow for an immediate recovery. 

[BT3-041] Cherubimon meanwhile has slower recovery (once every attack/turn) but by recovering from trash allows you to control what you will draw from the security following Wargreymon’s effect. For example, resolving Cherubimon’s effect to return a LV3 digimon from your trash to the top of your security, followed by Wargreymon allowing you to draw that very LV3 and then played for free using Angewomon’s inheritable effect.