Can 4 Stars Beat IS#4 Difficulty 15 Without Relics?

Rules:
I can't pick up any Relic, if I'm forced into it it's a reset.
All relics that Give squad and/or deploy limit are excepted and OK to use
Relics that give hope/ingots/life points are fine.
Runes that give combat buffs (HP+, ASPD+, Redep Time+) Are Banned.
This will be a long grind

[@Gredoxx]

Bro Damn

[@kawaiimercenary]

Mousse!!!

[@Victorvonbass]

I saw Mousse so I clicked the video eventhough I hate IS.

[@DrSilvergun]

clickbait has served it's purpose

[@hoteny]

No im not schizophrenic, I know there was a video with the same title. There was a mr. boom there, and i know i asked “does that not count as combat item?”

[@DrSilvergun]

it's not a relic

[@hoteny]

@@DrSilvergun oh okay, well i didnt even clear is2 bear yet so i cant try is3 and is4 so i basically forgot those mechanics, sorry.
im very likely to kill bear with my current standing in is2 but i dont wanna risk losing so i dont play at all since 2 years