For all battles, the strategy is to blade, and hit very quickly. Have a healer dedicated to healing with some blades and traps for the hitter. Usually it's best to have at least one storm and one life on the team.
Yevgeny NightCreeper: Bring conviction tc so that you can blade freely and avoid constant stuns. Yevgeny and his minions shield a lot and a shatter is needed on the round you attack. Try to end the battle within four turns before he uses Weaver, or at least before his devastating myth cycle.
Shane: There's a strategy I use for Shane that I am very strict about. You will need a storm and someone with mass storm prism for this strategy. I, a life wizard learned mass storm prism just for Shane. The goal is to kill him within 3-4 rounds. It's okay if you mess up, it's best to repeat a strategy several times than face him in a one hour long battle. The strategy is called the steal charm strategy. The storm must have steal charm tc. Everyone else must have nothing at all in their decks except blades, and traps for the storm. The storm must enter battle last. Someone should have mass storm prism if all enemies are storm, or just a single convert if they're myth. On the first round, the person with prism uses it, everyone blade the storm, storm uses steal charm. Second turn, everyone blades/traps storm, storm uses storm blade. Third round, everyone blades/traps storm can either hit if they have a shadow pip with glow bug or blade again. Fourth round, if storm does not hit with glow bug, they may use sirens instead or storm lord. This strategy usually works if you're lucky. Luck is based on: if you go first, if all minions are myth, if pets don't heal (DO NOT BRING HEALING PETS), if Shane decides to stun, beguile, or remove blades. This strategy only takes a few minutes if it is successful. You do not need any healing spells, spams, only blades, traps, storm prism. Storm only needs a couple of storm blades, steal charm, attack
Malistaire the Undying: Malistaire welcomes all healing pets which are important. If there is an ice minion, bring pierce, if fire or balance, bring cleanse charms. Life wizard must pack sanctuaries and have doom and gloom tc. no feints, universal blades or traps allowed. Every four rounds, his skeletal dragon removes all blades. The best strategy is to trap Malistaire the first one or two cycles, then quickly blade and hit on the third. The life wizard should try to get up sanctuary as fast as they can when the battle starts. When it's the round where everyone hits, the life should use doom if the hits look like they're going to kill Malistaire. When Malistaire dies, he respawns with less health thanks to the doom. Every four turns, he will use an OP shadow attack on a random wizard so life wizards must prepare a big heal every four rounds. Attackers continue to trap, blade, and make note of the cycles and kill Malistaire when they're ready.
That was a messy note of everything I could think of in strategy. Sorry I didn't exactly write out all their rules, I just wrote strategies around the major cheats.
The most important tip: Work together! All the bosses have some cheats, but all can be overcome with good teamwork. In some cases you can blade others, but not yourself. In others you'll need to have one player doing damage while others buff. Darkmoor doesn't require any specific lineup of wizards, just those with patience and a willingness to cooperate.