Confused about 1 character's question in this context (MC is discussing with his party members, about the origin of the Demon King)


**Context: MC are discussing with his party members about the meaning of a
Demon King's saying ,after he had defeated her.**

**Then 1 of his party member ask him 1 question ,it's hard for my JP level to
fully understand what did she said here ,so much thanks if anyone can explain
to me its correct meaning - if my understanding is wrong.**

**「勇者さまだったのに、魔王になったからといって突然、世界征服って考えちゃうのですか？」**

More context below:

【Demon King】「妾を倒せば、お前が代わりになるだけだぞ」

【エマ】「え？……代わりって、どういうこと？」

【ルナ】「有史より、魔王は度々具現しては世界を混乱に陥れていました」

【ルナ】「……まさか、その歴代の魔王全てが、元は『勇者』だったということですか！？」

【MC】「理解が早いね、さすがルナ」

それならば原始の魔王は誰だったのかって疑問は残るが、今は横に置いておこう。

**【レン】「勇者さまだったのに、魔王になったからといって突然、世界征服って考えちゃうのですか？」 (my guess but not sure : "So
these people ,despite they were heroes, they will suddenly thinking about
world domination - after they have became Demon King ?" )**

【MC】「いい質問だね。レン」

かわいい妹を褒めるようにレンの頭を優しくなでてやる。

【レン】「えへへ」




so I think the point confused you are: からといって. Before that is reason, after is
the fact, "just because of the reason, the fact will happen? "is a doubt about
this inevitability.

Simply, you can understand it as: "So these people, despite they were heroes,
(despite)they have became Demon King, will suddenly thinking about world
domination?"

You can find more details here: [enter link description
here](https://nihongonosensei.net/?p=13340)

