I use a Fighter with the Polearm Master and Sentinel feats that has a reach of 10ft.
On my turn:
I used Ready as an action in order to attack any monster that came within my reach.
End my turn.
Enemy moved inside my reach which activates my Ready action. (1st attack).
Used my Reaction to attack since he entered my 10ft reach thanks to Polearm Master (2nd attack).
The monster's speed is now 0 and it can't reach me because of Sentinel.
Is this legal? Or can't a ready action overlap with reaction?