They can be used to block almost any card, from creatures to sorceries to artifacts to planeswalkers, so long as you have them ready to catch those cards in the exact moment an opponent tries to play them
You just need to decide on which subthemes suit your taste and wallet
One or two target creatures each get +2/+0 until end of turn
In the first group we have Vengevine, Prized Amalgam, Bloodghast, Nether Shadow and Scourge of Nel Toth
While he might not do much for Zombie strategies on his own, Thraximundar benefits from the resiliency of the kindred theme, since a 6/6 with haste which doesn't stay a 6/6 for long is going to be targeted down quickly
Not only do they offer Impulse Draw each turn, but they also provide additional effects, depending on what you draw