Deadpool is not the sort of guy that you could predict with even a reasonable accuracy. If at all there are is only one thing which is safe to assume about the Merc with a Mouth. He would continuously break the fourth wall and will annoy anybody who crosses his path even if it is Thanos or Ebony Maw. In fact, we think that he would have addressed Thanos by the name of ‘Cable’ only for some weird reason. He might not have been strong enough to beat Thanos or to overcome the might of Infinity Gauntlet, but, he might have simply frustrated the two clashing sides to the extent that they might have chosen to give up fighting altogether.
In any case, let’s have a look at some of the possible things that Deadpool might have done in that battle!