For A 'kids' Show There Is A Lot Of Death/near Death/thought To Be Dead - Tumblr Posts

He's a cockroach. Dude is genuinely cursed to not die (his closest is Seabound, but even then it's only "getting worse" and not "died/presumed dead/equivalent to death"), but instead brings death around him.

Spoilers for every season but Crystalized below;

Look at how many times the others have died with Jay there as a witness (not including Kai's Seabound CPR scene as Jay wasn't there, the OG4 presumed dead in SoG/Hunted because he was one of them, and no Crystalized):

Kai: (3) Nadakhan's Blade (Skybound) ; Gold Statue (Skybound) ; Cubed (Prime)

Nya: (3) - Tiger Widow poison (Skybound) ; Cubed (Prime) ; Sea (Seabound)

Lloyd: (5) - Nadakhan's Blade (Skybound) ; Gold Statue (Skybound); Garmadon punching him through a wall (SoG) ; Support beam collapse (March of the Oni) ; Cubed (Prime)

Cole: (5.5) - Ghost (Possession) + Nearly faded away (Day of the Departed) ; Nadakhan's Blade (Skybound) ; Gold Statue (Skybound) - The Fall (March of the Oni) ; Cubed (Prime)

Zane: (6.5) - Rebooted ; Gold Statue (Skybound) ; Nadakhan's Blade (Skybound) ; Knocked badly offline (Hands of Time) ; Knocked badly offline (SoG) ; Aspheera banishing him (Forbidden - Fire Chapter) ; Honourable Mention: Battery Zap (Prime), I guess you could also count the beetle (Fire Chapter) and when he temporarily vanishes due to time stuff (Hands of Time)

Pixal & Wu too (Pix in Rebooted, when she got dismantled in Tournament, when she got deleted in Skybound even if Jay didn't witness/know about that one, and when she temporarily vanished in Hands of Time), and Wu in the pilots, against the Great Devourer, Nadakhan's sword, and in the time vortex

There might be more; those are just the major moments that come to mind- and those are all ones Jay witnesses directly, some of which he even (directly or indirectly) causes or could feel guilty about (skybound, prime empire, seabound, ignoring Zane's vision in the Ice Chapter, being the one next to Cole in the rope chain in the Airjitzu Temple, etc.)

So yeah, if anyone's living forever, it's Jay