Cu Sidhes can learn Disco, and have Healing. They can also learn Conductive Blast to even further lower the victim's Energy Resist by half (in case your Sampire is using 100% Energy wep). The Unicorn can learn both Discord and Conductive Blast as well, and will spam them more often than the Cu, but it's not quite as tanky due to lower Health and no Healing. Although, it is completely immune to the Poison status.
The upcoming Triton however, is perfect for it. They can learn Discord and Conductive Blast, spam them more often than a Cu, have Healing, and also very high Resist skill (so virtually immune to Poison spell and debuffs).