What is better?

[Nickolas]

Rage spell
Healing spell

[SuperJia]

Depends ! Rage spell is used more than heal spell , but heal spell work great with giants

[mfishfan]

Rage spell
Healing spell

Like SuperJia said both spells are useful in their own way bit I like the rage spell better.

[Tigre]

I like rage spell as they speed troops up and make them do more damage which more than makes up for the heal of the healing spell in my opinion

[Rager]

Rage works best. Why else do you think supercell hasn't made lvl 6 rage? There isn't level 6 for things that they don't like or are OP. Goblins, rage and wall breakers, and when they did wall breakers everyone was crying on the forums.

[Chris2000]

Hi,
Rage spell is a must especially as you start attacking in crystal league. Heal spell (when upgraded) is very efficient too especially on giants and heavier troops. With the heal spell level 6 your basically doubling life of 12-15 level 6 giants. Very efficient on large villages...
- Chris

[Golden119]

Rage - To crush your enemies, see them driven before you, and to hear the lamentation of their women.