it doesn't seem like anyone has summarized it to far, but perhaps putting the detailed information about 4T13 Mind Spike usage into OP would be worthwhile.
HowToPriest has the longer writeup, but the gist of it seems to be:
- MF x2, clip after 2 ticks each time (stacks Evangelism to 5)
- MS x2
- SF
- AA + SP trinket, if any (Bottled Wishes) + MB
- MS x3
- MF, clip as soon as MB becomes available
- MB
- MS x3
- MF, clip as soon as MB becomes available
- MB
This rotation lets you get off 3 3-orb Mind Blasts, all three while AA (and optionally trinket proc) are active, 2 of those MBs with guaranteed crit and the third nearly so, and aligns the MBs with the Shadowfiend's slower attacks by using the MF filler. It also doesn't scale well with Heroism/Bloodlust, because then you tend to simply get off extra no-orb MS casts. It may help if you cast SF while in melee range of the target.
In execution phase, MF can be replaced with a double SW:
D as a filler before second MB (AA+MB,MS x3, SW:
D x2, MB), and the third MB will still benefit from the triple orbs and AA. This would also give one the opportunity to move around a bit (SW:
D and double-Mindmelt MBs being instant), increasing the chance of Shadowy Apparition procs.
Also, it may be worth noting that Engineering throws a minor wrench into this if you have Bottled Wishes, because Synapse Spring proc places a 10-second CD on it, which is something worth keeping in mind.