I don't think it's a good addition to Test and Fina, unless you are very experienced and it's your precontest cutting cycle.
Halo greatly increase aggressiveness, so does Fina, and Test is not bad for it as well. It's a good coctail if you want eventually kill someone.
And, Halo has very little use, if your goal is bulking, it will help a lot with strength, though.
Most people use 10-30mg/day for 2-3 weeks.
You have to consider also, that Halo is very bad for liver, worse then other oral steroids.