How can I improve my Gravekeeper's deck?

I was wondering if someone knows how I can improve this deck just as a control deck and possibly but highly unlikely, add some synchro power into this deck. thanks in advance for your suggestions.

Monsters(21):
GK Spy x3
GK Descendant x3
GK guard x2
GK Commandant x2
GK Assailant x2
GK Spear soldier
GK Chief x2 (excellent combo to tribute Visionary then bring bring visionary back)
GK Visionary x3
Mystic tomato
Charm of shabti (probably going to remove)
Legendary fiend (summoned by mystic tomato and would have 2200atk on your turn)
Newdoria

Spells(13):

Necrovalley x3
GK Stele (possibly add more)
Dark hole
Soul Exchange
MST x2
Book of moon
Allure of darkness
Swords of revealing light
Card destruction
Heavy storm

Traps( 8 ):
trap hole
Dark illusion
Magicians circle (really good with visionary, might add more)
Mirror force
Metal reflect slime
Rising Energy x2

All suggestions are considered, Also I'm thinking about turning this deck to a GK only deck but however I find it hard here in the UK to get GK support such as royal tribute and rite of spirit.

Thanks for taking the time to read this thread

3 recruiter (gravekeeper)