Yes, it destroys your opponents monsters if they get cocky with their summoning and choose to attack, but it does not deal any damage when triggered
Having flash is nice because you can wait most of the early turn cycle without exposing Archivst of Oghma to targeted removal
Despite this nature, both are usually included in deck lists as disruption, proving how strong they really are
There are quite a lot of rare and expensive Magic: The Gathering trading cards out there
For example, if my starting hand has two one-drops, three three-drops, a fancy item or action card, and a seven-drop, then I will usually keep one one-drop and one three-drop and bottom the other five
If you can afford it, this is the best EDH card on the market, but there are some better cards at ramping you up long-term