[quote=-AcE-]
Also I can imagine Isaak working behind the scenes to bring Acacia down!
[/quote]

It could make for an interesting plot point.

But without proof or evidence, he's go nothing going for him, and unless he can win over the other Slytherins (which I doubt he will), its going to be...difficult at best. Acacia is very good about not leaving evidence or...loose ends.