Iceclad rewrites battles: instead of comparing DP, you compare how many digivolution cards each Digimon has, security battles excluded. A small stack with ten sources beats a 15000 DP monster, which is why Iceclad decks care about Training and anything else that piles cards under the Digimon. Watch the tie rule, because equal stacks means both Digimon die.
16-35-1. <Iceclad> is a keyword effect where you compare the number of digivolution cards instead of DP when you battle using the Digimon with this effect, other than battles against Security Digimon. 16-35-2. <Iceclad> is a persistent effect. (For details, refer to 15-8-2 "Persistent Effects") 16-35-3. <Iceclad> is an effect that changes the rules of a battle. 16-35-4. When using <Iceclad> to compare the number of digivolution cards for two cards in a battle, the winner and loser of the battle are determined as follows. 16-35-4-1. The card with the higher number of digivolution cards is the winner. 16-35-4-2. The card with the lower number of digivolution cards is the loser. 16-35-4-3. If both have the same number of digivolution cards, both cards lose the battle.
Comprehensive Rules §16-35 — official rules page
12 cards carry this keyword:
Rule text © Bandai, quoted from the official Comprehensive Rules for reference. Combalo is not affiliated with Bandai.