The exact grammar in those Sanskrit lines may seem stylized, but the imagery can be translated naturally like below.
 
Note: I tried my best to find the meanings and the exact lines of the song with that heavy music. If you found that these are not accurate or need correction. I love to do it and I loved finding the meanings of those lines.
 
1. Shakamidira Shakamulaku Pravara
Shakamidira (Shakamu + Idi + Ra) is like an era or age
Shakamulaku is among those shakas (eras)
Pravara meansthe best, supreme, or most eminent.
 
Translation: “This is an era, the most supreme and greatest among all the eras.”
 
2. Shikharamuke Shirasu Vadhukagara
Shikharamuke is the highest mountain peak
Shirasu meansHead.
Vadhukagara meansto bow down or to tremble (a poetic variation of vanchaga or vanakaga)
In this context we can consider the highest peak of the mountains are bowing to this greatest coming era.
 
Translation: “An era so mighty that even the loftiest mountain peaks must bow their heads in awe.”
 
3. Sharavivara Sharasa Ravi Vasara
Sharavivara is being one with the sharpness of arrows
Sharasa is Intense, Passionate or Vibrant.
Ravi is the Sun
Vasara is being a day or a collection or rays
 
Translation: “Radiant and intense like the blazing rays of the sun, spreading across the day.”
 
4. Shishiramuke Nishida Rachukavara
Shisiramuke meaning – Even to the autumn/winter season (the season of shedding leaves and coldness)
Nishida (Nisheedhi) being the dark night or deep silence.
Rachukavara (Rachinchu + Varamu): Composing or creating a boon/gift.
 
Translation: “Even in the barren autumn season, the dark night is composing a beautiful boon of new hope.”
 
All these lines can be combined in a single sentence or in context as:
“This is the supreme era among all ages. Before its majesty, even the highest mountain peaks bow their heads. It shines with the fierce brilliance of the sun, and even in the most barren, lifeless autumn, its dark night creates a new boon of hope.”
 
My Personal vent on the song while I’m trying to figure out the lyrics from music:

Thaman. S is a great musician and great composer, and I really like his composing of songs or background music. However, in the recent times it is very hard to hear the lyrics of his song compositions. Coming to this very song, From the beginning of the song, it became hard for me to make out what the exact lyrics are may be because of the music and instrumental choice or the singer Kumara Vagdevi.
 
I don’t blame her on this as we have another song by Thanam in recent times in collaboration with Anirudh Ravichander – Hai Re song from Itllu Arjuna, it became hard to hear song lyrics. He needs to consider that as the good lyrics are overshadowed by the loud music. It is just my personal vent while I’m transcribing the lyrics and that also an issue for you as well. If not good for you. You have very good ears.
 
Lyricist Kalyan Chakravarthy has given extraordinary lyrics to the song, which with the translation can be summarized as greatness of the Warrior and his tales. The lyrics are uprising with motivation and as per the Video song, it is clearly stated that “No War is more Violent than Love.”