i want a good processor that can handle adobe after effects like a cake no lags

Budget?

If money is not a issue then just get an i7-5960x, overclock it to 4.2GHz, and call it a day.

If you want something that doesn't cost you the equivalent of an entire mid-tier gaming PC, get an i7-5820k. It has two fewer cores than the flagship 5960, but at a third of the price, and you can still use the X99 platform with it. The six cores will help AE performance over the non-HEDT i7 cpus as well.
 


Yes, that'd be good for after effects, but not good for anything super 3d heavy.
But some things to consider:
1) an h81 motherboard can't overclock your CPU, but your CPU is capable of overclocking, so you could upgrade to a z87/97 motherboard in the future to overclock.
2) You can add a graphics card later on if you want to do 3d stuff, i.e. games/3d modeling.
3) The power supply probably isn't very good, so you may need to replace it sooner rather than later.