please help friends I can`t beat undead

[Sharog]

Actually u can use ranged unit just fine, i went with shaman, hunter, royal thorn, griffin and arch mage.

Tactic:
#1 tower up behind the barricade with griffin on the otherside.
#2 send in griffin in front line to soak dmg.
#3, box urself up with summoned plants and totem (u probably need to wipe out some bone dragon in order to complete the build in)
#4, upkeep the griffin tank with mana spring and other necessary buffs (like the archmage shield)
#5, all range unit kill the crystal first (toke me about 4-5 turns)
#6, use time back / sacrifise to replenish the griffin stack.
#7, camp till crystal is destroyed + karador out of mana
#8, weaken the ranged unit after crystal is dead and when karador run out of mana u can then kill off the necro and the rest.

with this tactic u only take direct dmg from necro/archer and 3 random enemy melee + 1-2 bone dragon stack dmg.

with some luck u wont get a darkknight stack on u since they have so poor initiative.

Although in my game i do have the -30% griffin leadership requirement item.
combined with -50% from archmage shield and other buffs it can take quite some punishment and dish out alot of retaliation attacks.

[propetba]

I accept with information:Good combos are:Take heavy loss + Time Back. This is probably the best rage spell on higher difficulties.
Mass Magic Shackle (lv 3 distortion). This stops the necromancers from reviving other units. Very useful.
Glot's armor / Wall / Ice thorns. They are barriers to buy you a turn or two. The most basic armor and wall are the best - as they are the cheapest.

[BB Shockwave]

Agreed for most of the points. The keys to winning the battle is:

-Good unit composition. You'll want hard-hitting melee units for this battle, the "Bone" ability of the skeletons/bone dragons and the high defense of Karador makes ranged units inflict much less damage.

-Wipe out the stack of bone dragons in the first round before Karador can act. He will 100% certainly raise them - you can kill them again every round, making sure he will not cast Hypnotize or damage spells! He will always prefer the dragons to raising lower level units.

-Slow down the melee units with Ice Thorns - Black Knights wasted 5 rounds for me to get through them.

-Shamans are a key to the battle. Put totems on dead bodies (except bone dragons) to prevent raising.

-Kill everything and leave the crystal for last, then let the crystal resurrect one stack only, and use Rage Taking. Use Chargers from the gained rage, resurrect fallen stacks with this! Make sure you kill the raised stack before Karador could cast a spell when that unit gets his turn.

-I used (Level 25 paladin) Royal Snakes (with Feanora and Royal Snake ring), Griffins (Griffin Banner let me recruit more, they are your decoy/tank unit for this battle), Shamans (see above), Black Dragons (use them wisely, avoid getting hit/retaliated by strong units, use wake of fire against fire-weak troops like skeletons), Black Unicrons (good damage against undead).

[iregev]

a good setup that worked for me was:
priests, Inquistors, Necromancers, sprites and dryad.
First turn blind the necromancers and the shooters kill enemy skellies, the Necromancers raise dead twice then time back. - The enemy hordes barely made it through the gates because the shooters killed them and the necromancers raised them again.

[Ymarsakar]

A few tricks I used was to use my own necromancers to resurrect their bone dragons first. If I couldn't do that, I would step on the corpse with one of my troops and never leave.

The tanks were ancient vampires and red dragons. For the crystal, as a mage, I used a demon portal which summoned demoness, and used them to attack the crystal every round or so while the rest of my army fought off the enemy stacks.