Good god man. If cards drop at 50%, go get yourself a Thanatos, a GTB, a SinX Card, some Megingjards, Incantation Samurai, Valkyrie Randgris, Ghostring, and Tao Gunka perhaps and Amon Ra. And use a 4 Slot +10 Pike. Unless your server has a custom heavy spear with more than one slot.
Normal cards you'll want to look out for, Flame Skull, Gemini, Marc, Evil Druid, Thara Frog, Hydra, Skeleton Worker.
And having high defense on a server like that will only get you instantly dropped by SinX using Thanatos on a Specialty Jur. You'll need to work your vit around a bit so you don't end up getting dropped in one shot.