Here are those digimon showing their wills to not be deleted or to revenge you in a worse way. A Megidramon don't care or never care if he is destroyed, because after that he can summon a "Gallantmon" from trash or hand for free. A new Omegamon totally stubbornly wants to stay in the battle, he can trash 1 LV6 under his evolution source to avoid destroying or return to hand or deck, imagine if his digivolution source is Shoutmon DX base, how many LV6 digimon would be there.. Or a Omegamon X antibody can end opponent's attack by removing 2 cards under his evolution source, so we say your digimon powerless against X-antibody.
Other than that, we have a cheap to digivolve LV7 Zwart Defeat, if he dies then somebody needs to follow him to the graveyard, the thing is it is other graveyard, not his (the other side). And last but not least, the 15000DP LV7 digimon Armageddmon, you LV7 digimon with powerful "when digivolving" effect is pointless to appear if this digimon is still in the battle.