1. Buy Crystal of Magic to Afrasas, and buy robe of flame to all heroes cept Nanaricci. Buy armlets on raiksha if you're familar with using them. Also, buy sword of poison on Afrasas.
2. Always try to get the enemies from the very start points.
3. Always fill up ur inventories with slow potions, and use them if you feel like you're going to miss.
4. At the end when you have to block ways by destroying rocks, sell all items on all heroes and buy tank items to Ignes, all IAS/DMG items on Nanaricci.
*most important* Nanaricci only needs three sharp shooter bows during the enemy waves. Do NOT buy any expensive stuffs for him.
If you need more help, ask me >_>