Lex is able to see invisible targets if they are his current bounty. Be sure to stick close to your team if you're revealed while invisible.

His ultimate will completely ignore shields (Including Barik's ultimate) and instead will instead do direct health damage. Find a blindspot instead of trying to tank the damage as a frontline champion.

Tyra's Fire bomb is unaffected by Heaven or Blast shields. Be sure to avoid it at all costs unless absolutely necessary; Some healers such as Ying or Mal'Damba can prolong a frontlines' life in unavoidable situations.