|When an ally is Attack
Devicro is best used in a build focused on sacrificing allies, gaining the attack of the sacrificed cards. However, most Shades don't have particularly high attack (and the ones that do are best left on the field to keep attacking), so their main use is extracting more value from Shades that are on their last legs. However, even weak Shades can still block attacks, so the benefits of sacrificing a Shade may be outweighed by those of keeping it alive depending on the situation.
Since Devicro doesn't get the most value out of sacrifice, they are best paired with other sacrifice-oriented cards like Monch and Groff, making each sacrifice multiple times more useful. Chikichi is particularly noteworthy, as all their summoned Shades will give Devicro a massive attack boost.