Okay, overall in terms of mons your team looks solid, however the move sets on some are ineffective or generally useless.
Mandibuzz
This is one of the best and arguable essential for dark monos, it is bulky I has recovery and a decent speed. But the moveset doesn't give it justice,A more fitting moveset would be:
- Foul play(Just to break heavy hitters and set up physical sweepers)
- Brave Bird (anti fighting and bug is good for dark mono)
- Defog (every team hates hazards)
-Roost (Nice recovery)
And a decent item would be rocky helmet, and Evs should go something like max Hp, some in def and the reminder in speed, altho I do like a little special bulk, and you might too and for ability, overcoat gives u immunity to spore
Shiftry
This mon is genrally useless, and I understand the no item due to pickpocket, but you get screwed if the guy is holding any choice item. It would replace it with a special sweeper since you are kinda lacking in that area. A good mon would be zoroark.
Zoroark(replacement for shiftry)
-Night Daze (good stab and nice chance to lower accuracy, Dark pulse if u want to play it a little safer)
-Extrasensory(Anti fighting)
-Flamethrower(kills bugs)
-Nasty Plot(Nice SpAtk boost)
This a standard set and it would help your team a lot(if u use it right). For item, I suggest sash, so at least one nasty plot and Evs would be around max SpAtk and Speed with timid nature preferable
Hydreigon
Hydreigon works great with bisharp, due to resisting and being immune to each others weaknesses. However this set isn't that great, but ur not far off.
- Flamethrower (I hate bugs, u can tell)
-Dark pulse(General stab)
-Earth power(Coverage)
-Dragon pulse/meteor(STAB)
This set + scarf is decent and Max SpA and Speed with Modest nature
Sharpedo
Now this mon can be a potential mega but absol mega, imo, is better and sharpedo doesn't really add anything so I suggest replacing this with a T-Tar lead because u have no hazards and no special wall.
Tyranitar(Replacement for sharpedo)
-Thunder wave(love haxs)
-Stealth rocks(nice little switch in punishment)
-Stone edge(Nice strong stab)
-filler(I prefer fire blast for bug monos and bug/steel leads)
This set works well and with T-Tars already incredible bulk it can tank a few hits. Leftovers and SpD and Def investment with a little in speed. note - also great synergy with mandibuzz and overcoat
Bisharp
This set looks a little solid but lacks stopping power and the all important fairy coverage, iron head.
-Iron head(anti fairy)
-psycho cut/knock off(coverage/utility)
-Swords Dance(insane attack)
-sucker punch(Bisharp is slow af)
This works wonders and can sweep unprepared teams easily. Max Atk and Speed with jolly nature
Absol
I suggest this to be your mega pokemon, as it can be a good anti lead due to its mega ability, magic bounce and if u play it right, u can destroy neutral teams. And it is tons better the regular absol
-Swords Dance(Boosting 150 base atk, lovely)
-Play Rough (Nice coverage)
-Sucker Punch(Priority and destruction)
-Knock off(This gets KOs and utility)
play this right get a free SD and destroy stuff, Jolly , Max Atk and Speed
*btw this is my first RMT