They have dozens of offices in the UK and Germany, 13 in Netherlands, …
It hardly seems surprising (nor damning) to have one in Cyprus.
You might learn how tax havens work. Those of us familiar all went "Cyprus...shocker /s".
Deloitte Cyprus is a separate legal entity from all the other (separate, legal) Deloitte entities precisely so any consequences of tax evasion resulting from the...em...lax oversight in Cyprus don't impact all the other things called 'Deloitte'.
I wonder why Abramovich chose that office, some historical link to Cyprus no one has heard of?