Since you have mentioned you want a powerful motorcycle, we would recommend you look at the Triumph Scrambler 400X, KTM 250 Adventure and TVS Apache RTX 300 in the ADV / Scrambler category. Of the three, the Triumph bike is the most powerful, but it is also pleasantly usable inside the city, whereas the KTM and TVS are more do-it-all machines that will also be wonderful on a day-to-day basis. 

Coming to the Xpulse 421, there's no official communication from Hero on when it will be launched, so we would recommend going with any of the other options you are considering. 

Take a test ride of whichever option you shortlist before you choose. 

If you are comfortable with the heft and size of an adventure bike, then the KTM 250 Adventure and the TVS Apache RTX 300 are both sensible, smooth and comfortable options. Between the two, we'd recommend the RTX because it gives you more for your money. 

The TVS Ronin is a fantastic bike too, with a smooth engine and good comfort, so if you want something lighter and more manageable that's also easier on the wallet, you can consider the Ronin. If you're open to the idea of owning a Royal Enfield bike, then the Hunter 350 will also serve you well because it is smooth, comfortable and reliable.

We recommend a thorough test ride of all machines you shortlist before you make your purchase. 

Since you haven't specified your budget, we'll give you some options from both the same segment as well as one above. 

In a similar displacement and performance range as the FZ25, the Bajaj Pulsar N250 and TVS Apache RTR 200 4V are good options, and the Pulsar in particular has a great headlight spread. You should also look at the KTM 250 Adventure because it has more performance than your FZ, good highway manners and a bright headlight too. 

If you are open to stepping up to a 300cc machine, the TVS Apache RTX 300 will be a great option. It has even more performance than the aforementioned KTM. Moreover, its Top and BTO variants come with a very bright LED headlight that also has good spread and throw.

We recommend exhaustive test rides and seeing the headlight performance of each of the bikes you shortlist for yourself before going ahead with the purchase. 

For your usage, in the cruiser space, you can take a look at the Royal Enfield Classic / Bullet 350 as well as any of the three Honda CB350 models. All bikes have relaxed, smooth engines, spacious seats and great suspension comfort. 

In the ADV space, options like the TVS Apache RTX 300 and KTM 250 Adventure can be considered for their punchy - but not overwhelming - performance, spacious seats and comfortable ride quality, as well as luggage carrying capability. 

Take thorough test rides of all shortlisted options before you decide.

The TVS Apache RTX 300 and KTM 250 Adventure will both fit the bill for your needs. Both have spacious seats, will return decent fuel economy, have great suspension and ride comfort and should be light on the pocket. Do bear in mind that these bikes are significantly more powerful than the Unicorn you currently have, and if you want something that's more laidback, there are other options. 

Bikes like the Royal Enfield Bullet / Classic 350 and the three Honda CB350 models will also fit the bill if you don't mind their laidback character and retro looks. 

We recommend a thorough test ride before you choose. 

Considering your requirements, we would recommend you choose between the KTM 250 Adventure and TVS Apache RTX 300. Both have good performance, are spacious, have comfortable suspension, more than enough ground clearance and will be fuel efficient because of their smaller displacement. Between the two, our pick would be the RTX because of its lower price point while offering more performance and features. 

The most compelling option in the 300cc space currently is the TVS Apache RTX 300, with its peppy performance, great comfort and extensive feature list at a tantalizing price. Since this is a very new product, we would advise you to wait for a while before purchasing it, so any teething issues that emerge can be ironed out. Something that's similarly priced and capable is the KTM 250 Adventure, which is also worth considering.