Certainly some decks will have far more targets and some will have more important targets meaning some variance in the performance of the card based on matchup but this can be expected with most cards
Crypt Ghast Most perks Ive listed about Nirkana Revenant, Magus of the Coffers, and Bubbling Muck apply to Crypt Ghast as well, so rather than extoll the virtues of Urborg, Tomb of Yawgmoth and X spells for the 4th time, Ill instead start by saying 4 is a very reasonable mana cost for a one-sided mana doubler before moving on to the other half of Crypt Ghasts text box
If you are likely to die the next turn unless you draw a key removal spell, you may choose not to attack to ensure you draw those extra cards
For other purposes, however, if a card refers to your commander, it means either the legendary creature or the legendary Background enchantment
Otherwise, instead B.F.M
however, there are times you just want the buff they provide