Hello!

There are alot of different tactics against Undead: Spirit Walker (Sw) Raiders (Ensnare, rly useful) Bm/FS (wolves>fiends) SH as second hero (Heal+Hex) Here is another basic tactic, that actually works if you're focusing the fiends, and keep the dk hexed: Wyverns + FS/BM + TC/SH

Keep on harrassing the Dk, when you have reached lvl 3 with BM, otherwise you could harras with FS while the ud is creeping. Kick somes accos

Good luck!