i'd like summons to be killable, so the summoners have to respawn them.

Summons are largely just special effects added to skills, if they were able to be controlled in a more impactful manner, maybe that would be needed, but even then, summoning them only takes a second.

Summon is most game breaking mechanins in the game. Have both player immunity and ability to CC other players is way to much. Also if you range/semi range class they locking you on them and any range attack you do targeted them ( non target game btw)  as result you skills do no damage - because summons take no damage from players.

Also  bug that was fixed with Nova, when you can summon multiple summon, exist for other class, which make summon classes extremly powerfull. Surrondered by summons, summoner is protected from any range attacks ( no damage to summons) also most summon teleport behind attacker and imidiatelly stun him - what is that ? who even think about adding such fantasting mechanic ?

Summons must be ripped off player protection and ability to telport behind other players.