Raw?

[Jallorn]

As far as I can tell, by RAW, you could be a Paladin of Tyrrany and still get the bonus stuff when you take Blackguard. Now obviously, most DMs would call in Rule 0, but I have two questions for the playground: A. am I reading the RAW correctly, and B. would it actually be fairly balanced to let a Paladin of Tyrrany (who serves as the tank in a regular 5 man class) take the Blackguard class and gain the benefits of having paladin levels along with keeping his paladin abilities?

[ko_sct]

You are right; by Raw a Paladin of tyranny can take blackguard and get the bonus, for whether or not it is balanced, I guess it depend on what is the group.

If he's in a group with lot of tier 1 or 2 class, sure go for it, otherwise it might be little too cheesy.

[Private-Prinny]

A: From the DMG

A fallen paladin who becomes a blackguard gains all of the following abilities that apply, according to the number of paladin levels the character has.

Since you need to fall, you can't stack the benefits of Paladin of Tyranny/Slaughter with Blackguard, but I see no RAW issue with trading them out if you happen to fall beforehand.

B: Make the Paladin slightly stronger? Go for it. They need all the help they can get.

[Greenish]

It look to be solid to me. That, and decidedly mediocre. You might want to watch those saves though, since Divine Grace and Dark Blessing stack, I think.

[Vangor]

Pretty much everyone else qualifying to become a blackguard is allowed to keep the benefits of their previous class levels. The paladin is different due to having to fall to become evil to qualify, which removes class features. If you fell (rose?) as a paladin of tyranny before becoming a blackguard, you would qualify for the fallen paladin features, but those are only qualified for provided you remain fallen. Becoming a blackguard as a paladin of tyranny, works, and as for balance, you have a long way to go before threatening balance.