Adverb
In a formidable manner.
Source: Webster's dictionaryKnowledge is a weapon. I intend to be formidably armed. Terry Goodkind
The experience of pain or loss can be a formidably motivating force. John C. Maxwell
It is here that we see the dawn of hope: for no matter how formidably Communism bristles with tanks and rockets, no matter what successes it attains in seizing the planet, it is doomed never to vanquish Christianity. Aleksandr Solzhenitsyn
the constant risk that attends the exchanges of human beings formidably armed Source: Internet