You’re spouting nonsense. You start by saying:
I have an Arduino Leonardo that I am controlling with Blynk via ethernet shield.
Then you say:
and I don't want to purchase a wifi shield.
So, you’re not really controlling a Leonardo with a WiFi shield, right? But you want To. Got it. Sometimes you can do things for cheap. Sometimes those things can be easy. Rarely are things both cheap and easy but it can happen if you have an open mind.
If you just want to connect the Leonardo to the Internet, spend $2 on an ESP8266-01 module with AT firmware. Done. Cheap. But not as easy as a shield.
Next is both cheap and easy. A nodeMCU board, a driver transistor, IR diode and a handful of passives. That would replace the Leonardo and WiFi/Ethernet shield as your WiFi enabled Ir controller. GitHub - mdhiggins/ESP8266-HTTP-IR-Blaster: ESP8266 Compatible IR Blaster that accepts HTTP commands for u
GitHub - crankyoldgit/IRremoteESP8266: Infrared remote library for ESP8266/ESP32: send and receive infrare
And there are others...
Then there is your idea to repurpose a nodeMCU board as a WiFi shield. That’s the most difficult idea so far...