Carmilla, the fourth boss in "Castlevania: Lords of Shadow 2", can prove to be the first truly challenging boss. The game came out on February 25 so some of the first players are just now discovering how exciting and challenging this fight can be. The challenge is partially due to the fight being a three-parter that switches up the tactics each round.
After you choose the correct Maria to feed from, Carmilla will attack you.
First, she surrounds herself in a ball of energy. Each time she speaks she charges toward you. Just leap over the sphere of energy or dodge to the side. She will periodically summon servants to fight you as well. After defeating all of the servants, she causes a large area of effect with electricity on the ground; it spreads outward from her. You can leap over this when it reaches you. Generally, before this area of effect one, she will also summon a frontal cone of electricity that you can dodge to the side of.
In the second phase, when the orange health bar reaches about 1/4 remaining, she splits into multiples all around the field. These multiples will form a dome around them and begin circling around Dracula. They also do the electricity area of effect each time they speak, but this time it begins at the edges of the dome and proceeds inward, slowly, toward Dracula’s location. This is easy enough to leap over if you wait for it to shrink up. Just keep attacking any of the Carmillas to move on to the next stage.
During the third round, Carmilla summons a spectre to throw lightning in a frontal cone at you. Dodge out of the way of it and keep damaging Carmilla. The spectre may swing at you in a very telegraphed, drawing its arm back motion; this attack is blockable and easily read so block it and keep going. Carmilla will also throw wide walls of chaos fire at you. These walls need to be dodged to the right first then to the left. Finally, the spectre does an unblockable grab. It will show a red flashing icon and make a loud noise before trying to grab Dracula; simply dodge this.
You can also slip through the gate to feed on Marie using the newly obtained mist skill during this third portion of the fight.