It's never great to give your enemies the option of losing life to save their creatures, but black has plenty of ways to turn life loss to their advantage
[-2]: Create a 2/3 black Vampire creature token with flying and lifelink
Unlike Stickers, which fall off when moving into a hidden zone, Perpetually effects are applied permanently to a card for the rest of the game, regardless of zone changes
Fierce Guardianship Fierce Guardianship is arguably the most effective protection spell for Commander and ranks among the best blue cards MTG has ever designed for the format
Maybe you aren't dreaming of opening Sift (even though I am), but there's nothing wrong with taking one of these cards and having it give you a direction
By the same token, "Blue" ( Mythical Island ) reduces the damage your Pokmon take from attacks next turn by 10, which can sometimes make the difference between your Active Pokmon being knocked out or surviving